title: Abusing Findstr for Defense Evasion author: Furkan CALISKAN, @caliskanfurkan_, @oscd_initiative date: 2020/10/05 description: Attackers can use findstr to hide their artifacts or search specific strings and evade defense mechanism detection: SELECTION_1: EventID: 1 SELECTION_2: CommandLine: - '*findstr*' SELECTION_3: CommandLine: '*/V*' SELECTION_4: CommandLine: '*/L*' SELECTION_5: CommandLine: '*/S*' SELECTION_6: CommandLine: '*/I*' condition: (SELECTION_1 and SELECTION_2 and ((SELECTION_3 and SELECTION_4) or (SELECTION_5 and SELECTION_6))) falsepositives: - Administrative findstr usage id: bf6c39fc-e203-45b9-9538-05397c1b4f3f level: medium logsource: category: process_creation product: windows references: - https://github.com/LOLBAS-Project/LOLBAS/blob/master/yml/OSBinaries/Findstr.yml - https://oddvar.moe/2018/04/11/putting-data-in-alternate-data-streams-and-how-to-execute-it-part-2/ - https://gist.github.com/api0cradle/cdd2d0d0ec9abb686f0e89306e277b8f status: experimental tags: - attack.defense_evasion - attack.t1218 ruletype: SIGMA