diff --git a/rules/windows/defense_evasion_suspicious_execution_from_mounted_device.toml b/rules/windows/defense_evasion_suspicious_execution_from_mounted_device.toml new file mode 100644 index 000000000..ebaddbb1c --- /dev/null +++ b/rules/windows/defense_evasion_suspicious_execution_from_mounted_device.toml @@ -0,0 +1,80 @@ +[metadata] +creation_date = "2021/05/28" +maturity = "production" +updated_date = "2021/05/28" + +[rule] +author = ["Elastic"] +description = """ +Identifies when a script interpreter or signed binary is launched via a non-standard working directory. An attacker may +use this technique to evade defenses. +""" +from = "now-9m" +index = ["winlogbeat-*", "logs-endpoint.events.*", "logs-windows.*"] +language = "eql" +license = "Elastic License v2" +name = "Suspicious Execution from a Mounted Device" +references = [ + "https://www.microsoft.com/security/blog/2021/05/27/new-sophisticated-email-based-attack-from-nobelium/", + "https://www.volexity.com/blog/2021/05/27/suspected-apt29-operation-launches-election-fraud-themed-phishing-campaigns/", +] +risk_score = 47 +rule_id = "8a1d4831-3ce6-4859-9891-28931fa6101d" +severity = "medium" +tags = ["Elastic", "Host", "Windows", "Threat Detection", "Defense Evasion"] +timestamp_override = "event.ingested" +type = "eql" + +query = ''' +process where event.type == "start" and process.executable : "C:\\*" and + (process.working_directory : "?:\\" and not process.working_directory: "C:\\") and + process.parent.name : "explorer.exe" and + process.name : ("rundll32.exe", "mshta.exe", "powershell.exe", "pwsh.exe", "cmd.exe", "regsvr32.exe", + "cscript.exe", "wscript.exe") +''' + + +[[rule.threat]] +framework = "MITRE ATT&CK" +[[rule.threat.technique]] +reference = "https://attack.mitre.org/techniques/T1218/" +id = "T1218" +name = "Signed Binary Proxy Execution" +[[rule.threat.technique.subtechnique]] +reference = "https://attack.mitre.org/techniques/T1218/011/" +id = "T1218.011" +name = "Rundll32" + +[[rule.threat.technique.subtechnique]] +reference = "https://attack.mitre.org/techniques/T1218/005/" +id = "T1218.005" +name = "Mshta" + +[[rule.threat.technique.subtechnique]] +reference = "https://attack.mitre.org/techniques/T1218/010/" +id = "T1218.010" +name = "Regsvr32" + + + +[rule.threat.tactic] +reference = "https://attack.mitre.org/tactics/TA0005/" +id = "TA0005" +name = "Defense Evasion" +[[rule.threat]] +framework = "MITRE ATT&CK" +[[rule.threat.technique]] +reference = "https://attack.mitre.org/techniques/T1059/" +id = "T1059" +name = "Command and Scripting Interpreter" +[[rule.threat.technique.subtechnique]] +reference = "https://attack.mitre.org/techniques/T1059/001/" +id = "T1059.001" +name = "PowerShell" + + + +[rule.threat.tactic] +reference = "https://attack.mitre.org/tactics/TA0002/" +id = "TA0002" +name = "Execution"