action: global title: PowerShell Downgrade Attack id: b3512211-c67e-4707-bedc-66efc7848863 related: - id: 6331d09b-4785-4c13-980f-f96661356249 type: derived status: experimental description: Detects PowerShell downgrade attack by comparing the host versions with the actually used engine version 2.0 references: - http://www.leeholmes.com/blog/2017/03/17/detecting-and-preventing-powershell-downgrade-attacks/ tags: - attack.defense_evasion - attack.execution - attack.t1086 author: Harish Segar (rule) date: 2020/03/20 falsepositives: - Penetration Test - Unknown level: medium --- logsource: product: windows service: sysmon detection: selection: EventID: 1 CommandLine|re: '.*-[Vv][Ee][Rr][Ss][Ii][Oo][Nn] 2' Image|endswith: '\powershell.exe' condition: selection --- logsource: product: windows service: security detection: selection: EventID: 4688 CommandLine|re: '.*-[Vv][Ee][Rr][Ss][Ii][Oo][Nn] 2' Image|endswith: '\powershell.exe' condition: selection