diff --git a/rules/linux/defense_evasion_awk_binary_shell.toml b/rules/linux/defense_evasion_awk_binary_shell.toml new file mode 100644 index 000000000..938a5ecc0 --- /dev/null +++ b/rules/linux/defense_evasion_awk_binary_shell.toml @@ -0,0 +1,49 @@ +[metadata] +creation_date = "2022/02/24" +maturity = "production" +updated_date = "2022/02/24" + +[rule] +author = ["Elastic"] +description = """ +Identifies Linux binary awk abuse to breakout out of restricted shells or environments by spawning an +interactive system shell. This activity is not standard use with this binary for a user or system administrator. It indicates a potentially malicious actor attempting to improve the capabilities or stability of their access. +""" +from = "now-9m" +index = ["logs-endpoint.events.*"] +language = "eql" +license = "Elastic License v2" +name = "Linux Restricted Shell Breakout via awk Commands" +references = ["https://gtfobins.github.io/gtfobins/nawk/", + "https://gtfobins.github.io/gtfobins/mawk/"] +risk_score = 47 +rule_id = "10754992-28c7-4472-be5b-f3770fd04f2d" +severity = "medium" +tags = ["Elastic", "Host", "Linux", "Threat Detection", "Defense Evasion", "GTFOBins"] +timestamp_override = "event.ingested" +type = "eql" + +query = ''' +sequence by host.id, process.pid with maxspan=1m + [process where process.name : ("nawk", "mawk", "awk", "gawk") and process.args : "BEGIN {system(*)}"] + [process where process.parent.name : ("nawk", "mawk", "awk", "gawk") and process.name : ("sh", "bash")] +''' + + +[[rule.threat]] +framework = "MITRE ATT&CK" +[[rule.threat.technique]] +id = "T1548" +name = "Abuse Elevation Control Mechanism" +reference = "https://attack.mitre.org/techniques/T1548/" +[[rule.threat.technique.subtechnique]] +id = "T1548.004" +name = "Elevated Execution with Prompt" +reference = "https://attack.mitre.org/techniques/T1548/004/" + + + +[rule.threat.tactic] +id = "TA0005" +name = "Defense Evasion" +reference = "https://attack.mitre.org/tactics/TA0005/" \ No newline at end of file