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Enhanced Detection Coverage

The Enhanced detection set provides deep insight into system activity. This enables Sophos Linux Sensor (SLS) to more intelligently determine the security relevance of this activity and provide more context for incident analysts. However, this increased depth does require more processing power, and not all of the detections exclusive to Enhanced detection are suitable for each workload type.

For example, New File Executed can be enormously valuable to detect something like an attacker creating and running a malware payload. But, for environments running configuration management tools like Chef or Puppet, which frequently create and run new files, this same detection will instead generate a lot of events that aren't indicative of unwanted activity.

This document includes information regarding Core and Enhanced detections provided by Sophos. These include the following categories:

  • Detection Analytics: Core coverage that detects malicious behavior
  • Smart Policy: Provides additional context to incidents without generating false positive alerts for benign behavior

For more information see Categories of Detections.

Detection Analytics

Application Exploitation

Memory Corruption


Memory Marked Executable

Severity: Medium

Description

Memory is often marked executable in order to allow malicious code to execute when an application is being exploited. Alerts when a program sets heap or stack memory permissions to executable.

Deployment considerations

  • Can cause false positives for certain application servers.
  • Can introduce a negative performance impact for workloads with many process re-executions.

Attributes

Default stateDisabled
Content versions4.9.0+
Minimum sensor version5.0.0
Supports aarch64Yes
ATT&CK Techniques

T1203

T1106

T1190

Repeated Program Crashes

Severity: Medium

Description

Repeated program crashes could indicate that an attacker is attempting to exploit a memory corruption vulnerability, or that there is a stability issue in the affected application. Alerts when more than 5 instances of an individual program crash via segmentation fault.

Deployment considerations

  • None

Attributes

Default stateEnabled
Content versions4.9.0+
Minimum sensor version5.0.0
Supports aarch64Yes
ATT&CK Techniques

T1203

T1499.004

T1190


Userfaultfd Usage

Severity: High

Description

Certain Linux functionality is almost exclusively used when exploiting kernel vulnerabilities, usually with the goal of privilege escalation. Alerts when a binary executes the userfaultfd system call.

Deployment considerations

  • This detection will only alert for kernels that support userfaultfd (kernels 4.3+).

Attributes

Default stateEnabled
Content versions4.9.0+
Minimum sensor version5.0.0
Supports aarch64Yes
ATT&CK Techniques

T1203

T1106

T1068


Unusual application behavior

New File Executed in Container

Severity: High

Description

As containers are typically static workloads, this alert could indicate that an attacker has compromised the container and is attempting to install and run a backdoor. Alerts when a file that has been created or modified within 30 minutes is then executed within a container.

Deployment considerations

  • Can cause a negative performance impact on file-heavy workloads.

Attributes

Default stateDisabled
Content versions4.9.0+
Minimum sensor version5.0.0
Supports aarch64Yes
ATT&CK Techniques

T1204.002

New Script Executed in Container

Severity: High

Description

As containers are typically static workloads, this alert could indicate that an attacker has compromised the container and is attempting to install and run a backdoor. Alerts when a script that has been created or modified within 5 minutes is then executed within a container.

Deployment considerations

  • Currently only works for Python scripts.

Attributes

Default stateDisabled
Content versions4.10.0
Minimum sensor version4.10.0
Supports aarch64Yes
ATT&CK Techniques

Process Dumping Via Proc

Severity: Medium

Description

Adversaries may inject malicious code into processes via the /proc filesystem in order to evade process-based defenses as well as possibly elevate privileges. Alerts when a program uses ptrace (debugging) mechanisms to extract process data via the /proc filesystem.

Deployment considerations

  • Can generate benign/false-positive alerts from programs or scripts that regularly inspect proc entries.

Attributes

Default stateDisabled
Content versions4.9.0+
Minimum sensor version5.0.0
Supports aarch64Yes
ATT&CK Techniques

T1003.007

T1055.009


Remote Interactive Shell

Severity: High

Description

Remote Interactive shells are rare occurrences on modern production infrastructure. Alerts when a remote interactive shell is started if the shell was not created by SSHD.

Deployment considerations

  • None.

Attributes

Default stateDisabled
Content versions4.9.0+
Minimum sensor version5.0.0
Supports aarch64Yes
ATT&CK Techniques

T1059.004

T1190


Suspicious Interactive Shell

Severity: High

Description

Interactive shells are rare occurrences on modern production infrastructure. Alerts when an interactive shell is started with arguments commonly used for reverse shells.

Deployment considerations

  • None

Attributes

Default stateEnabled
Content versions4.9.0+
Minimum sensor version5.0.0
Supports aarch64Yes
ATT&CK Techniques

T1059.004


Suspicious Interactive Shell Advanced

Severity: High

Description

Interactive shells are rare occurrences on modern production infrastructure. Alerts when an interactive shell is started with arguments commonly used for reverse shells, started in a container, or started as a child of a network service that is not SSH.

Deployment considerations

  • Improves detection of interactive shells, but may result in increased false positives.
  • Can cause a negative performance impact on network-heavy workloads.

Attributes

Default stateDisabled
Content versions4.9.0+
Minimum sensor version5.0.0
Supports aarch64Yes
ATT&CK Techniques

T1059.004


Persistence

Kernel backdoors

BPF Program Executed

Severity: Medium

Description

The loading of a new BPF program could indicate that an attacker is loading a BPF-based rootkit to gain persistence and avoid detection. Alerts when a process loads a new privileged BPF program, if the process that is already part of an ongoing incident.

Deployment considerations

  • None

Attributes

Default stateEnabled
Content versions4.9.0+
Minimum sensor version5.0.0
Supports aarch64Yes
ATT&CK Techniques

T1014

T1562.006

T1547.006


Kernel Module Loaded

Severity: High

Description

Attackers commonly load malicious kernel modules (rootkits) to evade detection and maintain persistence on a compromised node. Alerts when a kernel module is loaded, if the program is already part of an ongoing incident.

Deployment considerations

  • None

Attributes

Default stateEnabled
Content versions4.9.0+
Minimum sensor version5.0.0
Supports aarch64Yes
ATT&CK Techniques

T1014

T1547.006


Resource hijacking

Cryptocurrency Miner Detected

Severity: Medium

Description

Opportunistic attackers often start cryptocurrency miners after compromising a node or container, usually indicating that the primary motive of the attacker is to hijack processor power. Alerts when a program with a name or arguments commonly associated with cryptocurrency miners is executed.

Deployment considerations

  • None

Attributes

Default stateEnabled
Content versions4.9.0+
Minimum sensor version5.0.0
Supports aarch64Yes
ATT&CK Techniques

T1496


Remote Access Tool Download

Remote Access Tool Download

Severity: Medium

Description

After gaining access to a system, an attacker may download different tools using curl, wget etc with bash commands. Download commands can be encoded using base64 encoding.

Deployment considerations

  • None

Attributes

Default stateDisabled
Content versions4.9.0+
Minimum sensor version5.0.0
Supports aarch64Yes
ATT&CK Techniques

T1219


Userland backdoors

Suspicious Program Name Executed-Space After File

Severity: Medium

Description

Attackers may create or rename malicious binaries to include a space at the end of the name in an effort to impersonate a legitimate system program or service. Alerts when a program is executed with a space after the program name.

Deployment considerations

  • None

Attributes

Default stateEnabled
Content versions4.9.0+
Minimum sensor version5.0.0
Supports aarch64Yes
ATT&CK Techniques

T1036.006

T1036.004

T1036.005

Evading detection

User Command Logging Evasion

Severity: Medium

Description

Evading command logging is common practice for attackers, but may also indicate that a legitimate user is performing unauthorized actions or trying to evade policy. Alerts when a change to user command history logging is detected, indicating that a user is attempting to evade command logging.

Deployment considerations

  • This detection requires uprobe support, present in kernels 4.8+.

Attributes

Default stateDisabled
Content versions4.9.0+
Supports aarch64Yes
Minimum sensor version5.0.0
Supports aarch64Yes
ATT&CK Techniques

T1070.003

T1562.003


System Exploitation

Tampering of security mechanisms

AppArmor Disabled In Kernel

Severity: High

Description

Modification of certain AppArmor attributes can only occur in-kernel, indicating that AppArmor has been disabled by a kernel exploit or rootkit. Alerts when the AppArmor state is changed from the AppArmor configuration detected when the sensor starts.

Deployment considerations

  • If the kernel in use doesn't use AppArmor, an error may be logged for this detection when the sensor starts.

Attributes

Default stateEnabled
Content versions4.9.0+
Minimum sensor version5.0.0
Supports aarch64Yes
ATT&CK Techniques

T1562.001


AppArmor Profile Modified

Severity: Medium

Description

Attackers may attempt to disable enforcement of AppArmor profiles as part of evading detection. Alerts when a command for modifying an AppArmor profile is executed, if it was not executed by a user in an SSH session.

Deployment considerations

  • None

Attributes

Default stateEnabled
Content versions4.9.0+
Minimum sensor version5.0.0
Supports aarch64Yes
ATT&CK Techniques

T1562.001


SELinux Disabled In Kernel

Severity: High

Description

Modification of certain SELinux attributes can only occur in-kernel, indicating that SELinux has been disabled by a kernel exploit or rootkit. Alerts when the SELinux state in the kernel has been changed from the SELinux configuration detected when the sensor starts.

Deployment considerations

  • If the kernel in use doesn't use SELinux, an error may be logged for this detection when the sensor starts.

Attributes

Default stateEnabled
Content versions4.9.0+
Minimum sensor version5.0.0
Supports aarch64Yes
ATT&CK Techniques

T1562.001


SELinux Enforcement Mode Disabled From Userland

Severity: High

Description

Attackers may disable enforcement mode as a precursor to making significant system changes. Alerts when SELinux enforcement mode is disabled.

Deployment considerations

  • None

Attributes

Default stateEnabled
Content versions4.9.0+
Minimum sensor version5.0.0
Supports aarch64Yes
ATT&CK Techniques

T1562.001


Container escapes

Container Escape via Kernel Exploitation

Severity: High

Description

Alerts when a program uses kernel functions commonly used in container escape exploits, indicating that an attacker is escalating privileges from container-access to node-access.

Deployment considerations

  • None

Attributes

Default stateEnabled
Content versions4.9.0+
Minimum sensor version5.0.0
Supports aarch64Yes
ATT&CK Techniques

T1611

T1068


Docker Socket Accessed

Severity: Medium

Description

The Docker socket is used to create and interact with containers on a node, and is a common target for attackers. Alerts when a Docker socket is accessed, if the connector isn't a known container management tool.

Deployment considerations

  • May issue unwanted alerts for legitimate container management tools.
  • Requires tuning of allowlists and blocklists for different environments.

Attributes

Default stateDisabled
Content versions4.9.0+
Minimum sensor version5.0.0
Supports aarch64Yes
ATT&CK Techniques

T1068

T1552.007

T1610

T1613


Privileged Container Launched

Severity: Low

Description

Privileged containers have direct access to host resources, leading to a greater impact when compromised. Alerts when a privileged container is launched, if the container isn't a known privileged image such as kube-proxy.

Deployment considerations

  • Can issue unwanted alerts for legitimate privileged containers. Requires fine-tuning of allowlists and blocklists for different environments.

Attributes

Default stateDisabled
Content versions4.9.0+
Minimum sensor version5.0.0
Supports aarch64Yes
ATT&CK Techniques

T1068


RunC Container Escape

Severity: High

Description

Alerts when a modification is detected of the runc binary by a non-package manager, such as with CVE-2019-5736.

Deployment considerations

  • Can cause a negative performance impact on file-heavy workloads.

Attributes

Default stateDisabled
Content versions4.9.0+
Minimum sensor version5.0.0
Supports aarch64Yes
ATT&CK Techniques

T1554

T1068

T1611


Userland Container Escape

Severity: High

Description

Many container escapes coerce the host to execute an in-container binary, resulting in the attacker gaining full control of the affected node. Alerts when a container-created file is executed from outside a container.

Deployment considerations

  • None

Attributes

Default stateEnabled
Content versions4.9.0+
Minimum sensor version5.0.0
Supports aarch64Yes
ATT&CK Techniques

T1068

T1611


Common kernel exploitation methods

Illegal Elevation Of Privileges

Severity: High

Description

Kernel privilege escalation exploits commonly enable an unprivileged user to gain root privileges without passing standard gates for privilege changes. Alerts when a program attempts to elevate privileges through unusual means.

Deployment considerations

  • Can issue false positive alerts on nodes with significant workloads.

Attributes

Default stateDisabled
Content versions4.9.0+
Minimum sensor version5.0.0
Supports aarch64Yes
ATT&CK Techniques

T1068


Kernel Exploit

Severity: High

Description

Internal kernel functions are not accessible to regular programs, and if called, are a strong indicator that a kernel exploit has executed and that the attacker has full control of the node. Alerts when a kernel function unexpectedly returns to userland.

Deployment considerations

  • None

Attributes

Default stateEnabled
Content versions4.9.0+
Minimum sensor version5.0.0
Supports aarch64Yes
ATT&CK Techniques

T1212

T1211

T1068

Kernel ROP

Severity: High

Description

Kernel ROP (return-oriented programming) exploits are often used to illegally elevate privileges or bypass other security measures. Alerts when ROP is detected in the kernel, specifically in a call to prepare_kernel_cred which is indicative of an exploit.

Deployment considerations

  • None

Attributes

Default stateEnabled
Content versions4.10.0
Minimum sensor version4.2.0
Supports aarch64Yes
ATT&CK Techniques

T1068


Processor-Level Protections Disabled

Severity: High

Description

SMEP and SMAP are processor-level protections that increase difficulty for kernel exploits to succeed, and disabling these restrictions is a common early step in kernel exploits. Alerts when a program tampers with the kernel SMEP/SMAP configuration.

Deployment considerations

  • This detection is not functional for kernels between v4.19 and v5.2 (inclusive) as kernel code changes removed visibility of attempts to modify SMEP/SMAP configuration.

Attributes

Default stateEnabled
Content versions4.9.0+
Minimum sensor version5.0.0
Supports aarch64No
ATT&CK Techniques

T1562.001


Smart Policy

File Activity

Changes to system binaries

Boot Files Modified

Severity: Medium

Description

If not performed by a trusted source (e.g. package manager or configuration management tool), modification of boot files could be indicative of an attacker modifying the kernel or its options in order to gain persistent access to a host. Alerts when changes are made to files in /boot, indicating installation of a new kernel or boot configuration.

Deployment considerations

  • Can cause a negative performance impact on file-heavy workloads.

Attributes

Default stateDisabled
Content versions4.9.0+
Minimum sensor version5.0.0
Supports aarch64Yes
ATT&CK Techniques

T1542.003


Indicator removal

Log Files Deleted

Severity: Low

Description

Log deletion not performed by a log management tool could indicate that an attacker is trying to remove indicators of compromise. Alerts on deletion of system log files.

Deployment considerations

  • Can cause a negative performance impact on file-heavy workloads.

Attributes

Default stateDisabled
Content versions4.9.0+
Minimum sensor version5.0.0
Supports aarch64Yes
ATT&CK Techniques

T1070.004

T1070.002


Userland backdoors

Modification Of Common System Utilities

Severity: Low

Description

Attackers may modify system utilities in order to execute malicious payloads whenever these utilities are run. Alerts when a common system utility is modified by an unauthorized process.

Deployment considerations

  • Can cause a negative performance impact on file-heavy workloads.

Attributes

Default stateDisabled
Content versions4.9.0+
Minimum sensor version5.0.0
Supports aarch64Yes
ATT&CK Techniques

T1543


Configuration changes

Root Certificate Store Modified

Severity: Medium

Description

Modification of the root certificate store could indicate the installation of a rogue certificate authority, enabling interception of network traffic or bypass of code signature verification. Alerts when a system CA certificate store is changed.

Deployment considerations

  • Can cause a negative performance impact on file-heavy workloads.

Attributes

Default stateDisabled
Content versions4.9.0+
Minimum sensor version5.0.0
Supports aarch64Yes
ATT&CK Techniques

T1553.004

Sudoers File Modified

Severity: Medium

Description

Modifications to the sudoers file could indicate an attempt to escalate privileges or bypass password authentication. Alerts when the sudoers file is modified.

Deployment considerations

  • Can cause a negative performance impact on file-heavy workloads.

Attributes

Default stateDisabled
Content versions4.10.0
Minimum sensor version4.4.0
Supports aarch64Yes
ATT&CK Techniques

T1548.003


Privileged file operations

Setuid/Setgid Bit Set On File

Severity: Medium

Description

Setting setuid/setgid bits can be used to provide a persistent method for privilege escalation on a node. Alerts when the setuid or setgid bit's set on a file with the chmod family of system calls.

Deployment considerations

  • None

Attributes

Default stateEnabled
Content versions4.9.0+
Minimum sensor version5.0.0
Supports aarch64Yes
ATT&CK Techniques

T1548.001

System configuration changes

Systemd Unit File Modified

Severity: Medium

Description

Changes to systemd units could result in security controls being relaxed or disabled, or the installation of a malicious service. Alerts whenever a systemd unit file is modified by a program other than systemctl.

Deployment considerations

  • Can cause a negative performance impact on file-heavy workloads.

Attributes

Default stateDisabled
Content versions4.9.0+
Minimum sensor version5.0.0
Supports aarch64Yes
ATT&CK Techniques

T1562.001

T1543.002


User Scoped Systemd Service Created

Severity: Medium

Description

User-scoped systemd services start whenever a user first establishes a session, and run until the last session for the user is closed. This type of service is rare, and could indicate that an attacker is attempting to establish persistent access to a system. Alerts whenever a user-scoped systemd unit file is created.

Deployment considerations

  • Can cause a negative performance impact on file-heavy workloads.

Attributes

Default stateDisabled
Content versions4.9.0+
Minimum sensor version5.0.0
Supports aarch64Yes
ATT&CK Techniques

T1562.001

T1543.002


Unusual Files Created

Hidden File Created

Severity: Low

Description

Attackers often create hidden files as a means of obscuring tools and payloads on a compromised host. Alerts when a hidden file is created by a process associated with an ongoing incident.

Deployment considerations

  • Can cause a negative performance impact on file-heavy workloads.

Attributes

Default stateDisabled
Content versions4.9.0+
Minimum sensor version5.0.0
Supports aarch64Yes
ATT&CK Techniques

T1564.001


Network Activity

Lateral movement

Network Service Scanner Executed

Severity: Medium

Description

An attacker or rogue user may use or install these programs to survey connected networks for additional nodes to compromise. Alerts when common network scanning program tools are executed.

Deployment considerations

  • None

Attributes

Default stateEnabled
Content versions4.9.0+
Minimum sensor version5.0.0
Supports aarch64Yes
ATT&CK Techniques

T1046

T1018


Network sniffing

Network Sniffing Program Executed

Severity: Medium

Description

An attacker or rogue user may execute network sniffing commands to capture credentials, PII, or other sensitive information. Alerts when a program is executed that allows network capture.

Deployment considerations

  • None

Attributes

Default stateEnabled
Content versions4.9.0+
Minimum sensor version5.0.0
Supports aarch64Yes
ATT&CK Techniques

T1040


Discovery

Cloud Metadata API Accessed

Severity: Medium

Description

Attackers commonly enumerate cloud environment details and gain access to instance credentials by accessing the cloud provider's metadata API. Alerts when a program accesses the cloud metadata API, if the program is already part of an ongoing incident.

Deployment considerations

  • None

Attributes

Default stateEnabled
Content versions4.9.0+
Minimum sensor version5.0.0
Supports aarch64Yes
ATT&CK Techniques

T1552.005


Network Connection Enumeration Via Program

Severity: Low

Description

A common post-exploitation activity for attackers involves discovering adjacent hosts and networks prior to lateral movement. Alerts when a program associated with network connection enumeration is executed, if the program is already part of an ongoing incident.

Deployment considerations

  • None

Attributes

Default stateEnabled
Content versions4.9.0+
Minimum sensor version5.0.0
Supports aarch64Yes
ATT&CK Techniques

T1049

T1018


Network service behavior

Network Service Created

Severity: Medium

Description

Attackers may start a new network service to provide easy access to a host after compromise. Alerts when a program starts a new network service, if the program is already part of an ongoing incident.

Deployment considerations

  • None

Attributes

Default stateDisabled
Content versions4.9.0+
Minimum sensor version5.0.0
Supports aarch64Yes
ATT&CK Techniques

Outbound connections

Remote File Copy Detected

Severity: Medium

Description

Use of file transfer tools could indicate that an attacker is attempting to move toolsets to additional hosts or exfiltrate data to a remote system. Alerts when a program associated with remote file copying is executed, if the program is already part of an ongoing incident.

Deployment considerations

  • None

Attributes

Default stateEnabled
Content versions4.9.0+
Minimum sensor version5.0.0
Supports aarch64Yes
ATT&CK Techniques

T1570

T1048.002


Unusual Outbound Connection Detected

Severity: Low

Description

Command and Control channels and cryptocoin miners often create new outbound network connections on unusual ports. Alerts when a program initiates a new connection on an uncommon port, if the program is already part of an ongoing incident.

Deployment considerations

  • Can cause a negative performance impact on network-heavy workloads.

Attributes

Default stateDisabled
Content versions4.9.0+
Minimum sensor version5.0.0
Supports aarch64Yes
ATT&CK Techniques

T1571


Process Activity

Compiler usage

Compiler usage

Severity: Low

Description

An attacker may compile a custom backdoor or kernel exploit on a node to ensure compatibility with the node. Alerts when a program is executed that compiles a binary.

Deployment considerations

  • Can cause a decrease in performance for workloads that run build jobs regularly

Attributes

Default stateDisabled
Content versions4.9.0+
Minimum sensor version5.0.0
Supports aarch64Yes
ATT&CK Techniques

T1027.004


Abnormal process execution

New File Executed

Severity: Medium

Description

Newly created files from sources other than system update programs may be backdoors, kernel exploits, or part of an exploitation chain. Alerts when a file that has been created or modified within 30 minutes is then executed, excluding files created by system update programs.

Deployment considerations

  • Can cause a negative performance impact on file-heavy workloads.

Attributes

Default stateDisabled
Content versions4.9.0+
Minimum sensor version5.0.0
Supports aarch64Yes
ATT&CK Techniques

T1024.002

New Script Executed

Severity: Medium

Description

Newly created scripts from sources other than system update programs may be backdoors, kernel exploits, or part of an exploitation chain. Alerts when a file that has been created or modified within 5 minutes is then executed by a script interpreter, excluding files created by system update programs.

Deployment considerations

  • Currently only works for Python scripts.

Attributes

Default stateDisabled
Content versions4.10.0
Minimum sensor version4.10.0
Supports aarch64Yes
ATT&CK Techniques


Debugging

Process Injection

Severity: Medium

Description

Use of process injection techniques commonly indicates that a user is debugging a program, but may also indicate that an attacker is reading secrets from or injecting code into other processes. Alerts when a program uses ptrace (debugging) mechanisms to interact with another process.

Deployment considerations

  • None

Attributes

Default stateEnabled
Content versions4.9.0+
Minimum sensor version5.0.0
Supports aarch64Yes
ATT&CK Techniques

T1055.008


Scheduled task changes

Scheduled Tasks Modified Via File

Severity: Medium

Description

Modifying scheduled tasks is a common method for establishing persistence on a compromised node. Alerts when a cron-related file is modified, indicating a change to scheduled job configurations.

Deployment considerations

  • Can cause a negative performance impact on file-heavy workloads.

Attributes

Default stateDisabled
Content versions4.9.0+
Minimum sensor version5.0.0
Supports aarch64Yes
ATT&CK Techniques

T1053.003


Scheduled Tasks Modified Via Program

Severity: Medium

Description

Modifying scheduled tasks is a common method for establishing persistence on a compromised node. Alerts when the "crontab", "at", or "batch" commands are used to modify scheduled task configurations.

Deployment considerations

  • None

Attributes

Default stateEnabled
Content versions4.9.0+
Minimum sensor version5.0.0
Supports aarch64Yes
ATT&CK Techniques

T1053.003

T1053.001


System configuration changes

Systemctl Usage Detected

Severity: Medium

Description

Changes to systemd units could result in security controls being relaxed or disabled, or the installation of a malicious service. Alerts when the systemctl command is used to modify systemd units.

Deployment considerations

  • None

Attributes

Default stateEnabled
Content versions4.9.0+
Minimum sensor version5.0.0
Supports aarch64Yes
ATT&CK Techniques

T1562.001

T1543.002

T1489


Discovery

Account Enumeration Via Program

Severity: Low

Description

Attackers will often use account enumeration programs to determine their level of access and to see if other users are currently logged in to the node. Alerts when a program associated with account enumeration is executed, if the program is already part of an ongoing incident.

Deployment considerations

  • None

Attributes

Default stateEnabled
Content versions4.9.0+
Minimum sensor version5.0.0
Supports aarch64Yes
ATT&CK Techniques

T1087.001

T1087.002

T1069.001

T1069.002

T1069

T1033


File and Directory Discovery Via Program

Severity: Low

Description

Exploring file systems is common post-exploitation behavior for an attacker looking for credentials and data of interest. Alerts when a program associated with file and directory enumeration is executed, if the program is already part of an ongoing incident.

Deployment considerations

  • None

Attributes

Default stateEnabled
Content versions4.9.0+
Minimum sensor version5.0.0
Supports aarch64Yes
ATT&CK Techniques

T1083


Network Configuration Enumeration Via Program

Severity: Low

Description

Attackers can interrogate local network and route information to identify adjacent hosts and networks ahead of lateral movement. Alerts when a program associated with network configuration enumeration is executed, if the program is already part of an ongoing incident.

Deployment considerations

  • None

Attributes

Default stateEnabled
Content versions4.9.0+
Minimum sensor version5.0.0
Supports aarch64Yes
ATT&CK Techniques

T1016

T1018


Process Enumeration Via Program

Severity: Low

Description

Attackers often list running programs in order to identify the purpose of a node and whether any security or monitoring tools are in place. Alerts when a program associated with process enumeration is executed, if the program is already part of an ongoing incident.

Deployment considerations

  • None

Attributes

Default stateEnabled
Content versions4.9.0+
Minimum sensor version5.0.0
Supports aarch64Yes
ATT&CK Techniques

T1057


System Information Enumeration Via Program

Severity: Low

Description

Attackers will commonly execute system enumeration commands to determine Linux kernel and distribution versions and features, often to identify if the node is affected by specific vulnerabilities. Alerts when a program associated with system information enumeration is executed, if the program is already part of an ongoing incident.

Deployment considerations

  • None

Attributes

Default stateEnabled
Content versions4.9.0+
Minimum sensor version5.0.0
Supports aarch64Yes
ATT&CK Techniques

T1082


Data collection

Data Archived Via Program

Severity: Low

Description

After gaining access to a system, an attacker may create a compressed archive of files to reduce the size of data for exfiltration. Alerts when a data compression program is executed, if the program is already part of an ongoing incident.

Deployment considerations

  • None

Attributes

Default stateEnabled
Content versions4.9.0+
Minimum sensor version5.0.0
Supports aarch64Yes
ATT&CK Techniques

T1560.001


Data destruction

Data Destruction Via Program

Severity: Medium

Description

Data destruction performed by a non-trusted process may indicate that an attacker is trying to remove indicators of compromise or disrupt a node. Alerts when common tools for destroying data are used, if the process is already part of an ongoing incident.

Deployment considerations

  • None

Attributes

Default stateEnabled
Content versions4.9.0+
Minimum sensor version5.0.0
Supports aarch64Yes
ATT&CK Techniques

T1485

T1561.001

T1561.002

T1070.004


Log Daemon Tampering

Log Daemon Tampering

Severity: Medium

Description

Attempts to tamper with log daemons may indicate that an attacker is trying to remove indicators of compromise and hide their trails. Alerts when daemon control programs are invoked with specific arguments, if the process is already part of an ongoing incident.

Deployment considerations

  • None

Attributes

Default stateEnabled
Content versions4.9.0+
Minimum sensor version5.0.0
Supports aarch64Yes
ATT&CK Techniques

T1070


User Activity

User account changes

Account Modification

Severity: Medium

Description

Attackers may directly modify identity-related files to add a new user to the system. Alerts when a file related to identity management is modified by a program unrelated to updating existing user information.

Deployment considerations

  • Can cause a negative performance impact on file-heavy workloads.
  • Deprecated: This detection has been superceded by 'New System User Added', and will be removed in the next major release (5.0).

Attributes

Default stateDisabled
Content versions4.9.0+
Minimum sensor version5.0.0
Supports aarch64Yes
ATT&CK Techniques

T1136.001


New System User Added

Severity: Medium

Description

An attacker may add a new user to a host to provide a reliable method of access. Alerts if a new user entity is added to the local account management file /etc/passwd, if the entity is not added by a system update program.

Deployment considerations

  • Can cause a negative performance impact on file-heavy workloads.

Attributes

Default stateDisabled
Content versions4.9.0+
Minimum sensor version5.0.0
Supports aarch64Yes
ATT&CK Techniques

T1136.001


Password Database Modification

Severity: High

Description

Attackers may directly modify identity-related files to add a new user to the system. Alerts when a file related to user passwords is modified by a program unrelated to updating existing user information.

Deployment considerations

  • Can cause a negative performance impact on file-heavy workloads.

Attributes

Default stateDisabled
Content versions4.9.0+
Minimum sensor version5.0.0
Supports aarch64Yes
ATT&CK Techniques

T1136.001

T1098


User Account Created Via CLI

Severity: High

Description

Adding a new user is a common step for attackers when establishing persistence on a compromised node. Alerts when an identity management program is executed by a program other than a package manager.

Deployment considerations

  • None

Attributes

Default stateEnabled
Content versions4.9.0+
Minimum sensor version5.0.0
Supports aarch64Yes
ATT&CK Techniques

T1136.001


User Configuration Changes

Severity: Medium

Description

User profile and configuration files are often modified as a method of persistence in order to execute a program whenever a user logs in. Alerts when .bash_profile and bashrc (as well as related files) are modified by a program other than a system update tool.

Deployment considerations

  • Can cause a negative performance impact on file-heavy workloads.

Attributes

Default stateDisabled
Content versions4.9.0+
Minimum sensor version5.0.0
Supports aarch64Yes
ATT&CK Techniques

T1037.004

T1546.004

SSH Authorized Keys Modification

Severity: Medium

Description

Adding a new SSH public key is a common method for gaining persistent access to a compromised host. Alerts when an attempt to write to a user's SSH authorized_keys file is observed, if the program is already part of an ongoing incident.

Deployment considerations

  • Can cause a negative performance impact on file-heavy workloads.

Attributes

Default stateDisabled
Content versions4.9.0+
Minimum sensor version5.0.0
Supports aarch64Yes
ATT&CK Techniques

T1098.004

T1078.003


Risky developer activity

Shell Command Executed

Severity: Low

Description

This detection logs commands executed by a valid system user via SSH.

Deployment considerations

  • Can result in a high volume of notifications.

Attributes

Default stateDisabled
Content versions4.9.0+
Minimum sensor version5.0.0
Supports aarch64Yes
ATT&CK Techniques

T1059.004


User Command History Cleared

Severity: Medium

Description

Deleting the history file is unusual, commonly performed by attackers hiding activity, or by legitimate users intending to evade audit controls. Alerts when command line history files are deleted.

Deployment considerations

  • Can cause a negative performance impact on file-heavy workloads.

Attributes

Default stateDisabled
Content versions4.9.0+
Minimum sensor version5.0.0
Supports aarch64Yes
ATT&CK Techniques

T1070.003


User Login Via SSH

Severity: Low

Description

Alerts when an interactive shell process is started by a valid system user via SSH.

Deployment considerations

  • None

Attributes

Default stateEnabled
Content versions4.9.0+
Minimum sensor version5.0.0
Supports aarch64Yes
ATT&CK Techniques

T1078.002

T1078.003

T1059.004

T1133


Privileged command usage

User Execution Of su Command

Severity: Medium

Description

Explicit escalation to the root user decreases the ability to correlate privileged activity to a specific user. Alerts when the 'su' command is executed.

Deployment considerations

  • None

Attributes

Default stateEnabled
Content versions4.9.0+
Minimum sensor version5.0.0
Supports aarch64Yes
ATT&CK Techniques

T1548.003

User Execution Of sudo Command

Severity: Medium

Description

Alerts when the 'sudo' command is executed.

Deployment considerations

  • None

Attributes

Default stateEnabled
Content versions4.9.0+
Minimum sensor version5.0.0
Supports aarch64Yes
ATT&CK Techniques

T1548.003


User execution of unwanted sudo command

Severity: Medium

Description

Some commands run with sudo privileges are rarely used legitimately by system administrators and could indicate an account has been compromised. Alerts when 'sudo' is used to execute privileged commands common to post-exploitation activities.

Deployment considerations

  • None

Attributes

Default stateEnabled
Content versions4.9.0+
Minimum sensor version5.0.0
Supports aarch64Yes
ATT&CK Techniques

T1548.003


Abnormal process execution

Credential Enumeration Detected

Severity: Low

Description

Attackers and rogue users may search for passwords or other credentials after gaining access to a system, and may use these credentials to compromise additional hosts or services. Alerts when common password enumeration commands are issued in an interactive shell, if the shell is part of an ongoing incident.

Deployment considerations

  • None

Attributes

Default stateDisabled
Content versions4.9.0+
Minimum sensor version5.0.0
Supports aarch64Yes
ATT&CK Techniques

T1552.001