Detections

Explore public detection logic contributed by the community across SIEM and rule languages.

1,052 detections

The analytic detects the creation of the `doas.conf` file on a Linux host. This file is used by the `doas` utility to allow standard users to perform tasks as root, similar to `sudo`. The detection leverages filesystem data, focusing on the creation of the `doas.conf` file. This activity is significant because it can indicate an attempt to gain elevated privileges, potentially by an adversary. If confirmed malicious, this could allow an attacker to execute commands with root privileges, leading to full system compromise.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0029
The analytic detects suspicious access or modification of the sshd_config file on Linux systems. It focuses on command-line executions involving processes like "cat," "nano," "vim," and "vi" accessing the sshd_config file. Unauthorized changes to sshd_config can allow threat actors to redirect port connections or use unauthorized keys, potentially compromising the system, leading to unauthorized access, privilege escalation, or persistent backdoor access.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0029
The following analytic detects the execution of a command to enable all SysRq functions on a Linux system, a technique associated with the AwfulShred malware. It leverages Endpoint Detection and Response (EDR) data to identify processes executing the command to pipe bitmask '1' to /proc/sys/kernel/sysrq. This activity is significant as it can indicate an attempt to manipulate kernel system requests, which is uncommon and potentially malicious. If confirmed, this could allow an attacker to reboot the system or perform other critical actions, leading to system instability or further compromise.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0029
Detects programs that connect to known malware callback ports based on threat intelligence reports.
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
2 years ago
001
Yara rule that detects Sshdinjector backdoor.
ReversingLabs Yara@ReversingLabsYara
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ReversingLabs Yara
2 years ago
001
Detects command line patterns associated with the use of Pnscan for sending and receiving binary data across the network.
This behavior has been identified in a Linux malware campaign targeting Docker, Apache Hadoop, Redis, and Confluence and was previously used by the threat actor known as TeamTNT
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
2 years ago
000
Detects the execution of a shell as sub process of "rsync" without the expected command line flag "-e" being used, which could be an indication of exploitation as described in CVE-2024-12084. This behavior is commonly associated with attempts to execute arbitrary commands or escalate privileges, potentially leading to unauthorized access or further exploitation.
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
2 years ago
001
Detects the use of the "rsync" utility to execute a shell. Such behavior may be associated with privilege escalation, unauthorized command execution, or to break out from restricted environments.
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
2 years ago
000
This rule detects the execution of common Linux utilities used for process discovery. Adversaries often use these commands (atop, htop, pgrep, ps, pstree, top) to gather information about running processes on a system, which helps them understand the environment and plan subsequent actions. This information can reveal common software or applications running on systems within the network.
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
2 years ago
1020
Detects usage of system utilities such as "find", "tree", "findmnt", etc, to discover files, directories and network shares.
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
2 years ago
000
Detects a python process calling to the PTY module in order to spawn a pretty tty which could be indicative of potential reverse shell activity.
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
2 years ago
000
Detects the execution of python with calls to the socket and pty module in order to connect and spawn a potential reverse shell.
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
2 years ago
000
Detects the execution of common network scanning and reconnaissance tools on Linux systems. These tools are often used by adversaries to enumerate local or remote network services, identify open ports, and gather information about network topology and available hosts. The rule specifically looks for the execution of tools like netcat (when not in listen mode), nmap, hping, naabu, autorecon, and telnet.
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
2 years ago
1022
Detects known hacktool execution based on image name.
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
2 years ago
001
Detects execution of network scanning and reconnaisance tools. These tools can be used for the enumeration of local or remote network services for example.
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
2 years ago
000
Detects the use of the "apt" and "apt-get" commands to execute a shell or proxy commands.
Such behavior may be associated with privilege escalation, unauthorized command execution, or to break out from restricted environments.
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
2 years ago
000
Detects suspicious modifications to sensitive or critical system files on Linux systems. This rule monitors for common command-line utilities (like 'cat', 'echo', 'grep', 'vi', 'nano', 'sed') being used with output redirection ('>') or directly to edit files within critical system directories and configuration files. This activity could indicate an attacker attempting to alter system behavior, maintain persistence, or escalate privileges by modifying files that are not expected to change without explicit administrative planning.
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
2 years ago
20138
Detects attempts to clear logs on the system by identifying command-line executions of 'rm', 'shred', or 'unlink' targeting common log directories like '/var/log' and '/var/spool/mail'. Adversaries may clear system logs to hide evidence of an intrusion.
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
2 years ago
2052
This rule detects suspicious command-line patterns indicative of reverse shell attempts. It looks for various common techniques used to establish a reverse shell, including bash, sh, netcat, socat, Perl, Python, Ruby, and PHP one-liners that connect back to an attacker-controlled host. The rule also includes patterns for xterm reverse shells and specific shell commands often used in conjunction with reverse shells.
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
2 years ago
1046
This rule detects specific commands commonly used to remove or empty the syslog file on Linux systems. Adversaries may clear or modify system logs to remove evidence of their activities, hindering incident response and forensic analysis. The rule specifically looks for 'rm' commands with various flags (e.g., -r, -f, -rf) and 'mv' commands targeting '/var/log/syslog', as well as redirection to empty the file ('>/var/log/syslog').
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
2 years ago
1044
Detects the execution of the 'curl' command on Linux systems. This typically indicates an attempt to download files from a remote location or make web requests to external servers. This activity can be associated with adversaries transferring tools or communicating with command and control infrastructure.
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
2 years ago
1036
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