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Potential Reverse Shell via Suspicious Binary
editPotential Reverse Shell via Suspicious Binary
editThis detection rule detects the creation of a shell through a chain consisting of the execution of a suspicious binary (located in a commonly abused location or executed manually) followed by a network event and ending with a shell being spawned. Stageless reverse tcp shells display this behaviour. Attackers may spawn reverse shells to establish persistence onto a target system.
Rule type: eql
Rule indices:
- logs-endpoint.events.*
Severity: medium
Risk score: 47
Runs every: 5m
Searches indices from: now-9m (Date Math format, see also Additional look-back time
)
Maximum alerts per execution: 100
References:
Tags:
- Domain: Endpoint
- OS: Linux
- Use Case: Threat Detection
- Tactic: Execution
- Data Source: Elastic Defend
Version: 6
Rule authors:
- Elastic
Rule license: Elastic License v2
Rule query
editsequence by host.id, process.entity_id with maxspan=1s [ process where host.os.type == "linux" and event.type == "start" and event.action == "exec" and process.executable : ( "./*", "/tmp/*", "/var/tmp/*", "/var/www/*", "/dev/shm/*", "/etc/init.d/*", "/etc/rc*.d/*", "/etc/crontab", "/etc/cron.*", "/etc/update-motd.d/*", "/usr/lib/update-notifier/*", "/boot/*", "/srv/*", "/run/*", "/root/*", "/etc/rc.local" ) and process.parent.name : ("bash", "dash", "sh", "tcsh", "csh", "zsh", "ksh", "fish") and not process.name : ("curl", "wget", "ping", "apt", "dpkg", "yum", "rpm", "dnf", "dockerd") ] [ network where host.os.type == "linux" and event.type == "start" and event.action in ("connection_attempted", "connection_accepted") and process.executable : ( "./*", "/tmp/*", "/var/tmp/*", "/var/www/*", "/dev/shm/*", "/etc/init.d/*", "/etc/rc*.d/*", "/etc/crontab", "/etc/cron.*", "/etc/update-motd.d/*", "/usr/lib/update-notifier/*", "/boot/*", "/srv/*", "/run/*", "/root/*", "/etc/rc.local" ) and destination.ip != null and destination.ip != "127.0.0.1" and destination.ip != "::1" ] [ process where host.os.type == "linux" and event.action == "exec" and event.type == "start" and process.name : ("bash", "dash", "sh", "tcsh", "csh", "zsh", "ksh", "fish") and process.parent.name : ("bash", "dash", "sh", "tcsh", "csh", "zsh", "ksh", "fish") ]
Framework: MITRE ATT&CKTM
-
Tactic:
- Name: Execution
- ID: TA0002
- Reference URL: https://attack.mitre.org/tactics/TA0002/
-
Technique:
- Name: Command and Scripting Interpreter
- ID: T1059
- Reference URL: https://attack.mitre.org/techniques/T1059/
-
Sub-technique:
- Name: Unix Shell
- ID: T1059.004
- Reference URL: https://attack.mitre.org/techniques/T1059/004/
-
Tactic:
- Name: Command and Control
- ID: TA0011
- Reference URL: https://attack.mitre.org/tactics/TA0011/
-
Technique:
- Name: Application Layer Protocol
- ID: T1071
- Reference URL: https://attack.mitre.org/techniques/T1071/