{"id":"4c0aaedc-154c-4427-ada0-d80ef9c9deb6","title":"Process Access via TrolleyExpress Exclusion","description":"Detects a possible process memory dump that uses the white-listed Citrix TrolleyExpress.exe filename as a way to dump the lsass process memory","author":"Florian Roth (Nextron Systems)","status":"test","level":"high","date":"2022-02-10","modified":"2022-05-13","tags":["attack.stealth","attack.t1218.011","attack.credential-access","attack.t1003.001"],"technique_ids":["T1003.001","T1218.011"],"logsource":{"category":"process_creation","product":"windows"},"falsepositives":["Unknown"],"references":["https://twitter.com/_xpn_/status/1491557187168178176","https://www.youtube.com/watch?v=Ie831jF0bb0"],"source_path":"rules/windows/process_creation/proc_creation_win_citrix_trolleyexpress_procdump.yml","source_sha256":"736ddd3ccc7cc6ae1056837a36c5e59c9c282782cc081ff31431d87e7fb2ba31","source_url":"https://github.com/anpa1200/sigma/blob/b249e9683190cffdcaf188ccbfb90bf4759844e1/rules/windows/process_creation/proc_creation_win_citrix_trolleyexpress_procdump.yml","license":"Detection Rule License 1.1","license_url":"https://github.com/SigmaHQ/Detection-Rule-License/blob/main/LICENSE.Detection.Rules.md","yaml":"title: Process Access via TrolleyExpress Exclusion\nid: 4c0aaedc-154c-4427-ada0-d80ef9c9deb6\nstatus: test\ndescription: Detects a possible process memory dump that uses the white-listed Citrix TrolleyExpress.exe filename as a way to dump the lsass process memory\nreferences:\n    - https://twitter.com/_xpn_/status/1491557187168178176\n    - https://www.youtube.com/watch?v=Ie831jF0bb0\nauthor: Florian Roth (Nextron Systems)\ndate: 2022-02-10\nmodified: 2022-05-13\ntags:\n    - attack.stealth\n    - attack.t1218.011\n    - attack.credential-access\n    - attack.t1003.001\nlogsource:\n    category: process_creation\n    product: windows\ndetection:\n    selection:\n        CommandLine|contains:\n      # We assume that the lsass.exe process has a process ID that's between 700 and 999 and the dumper uses just the PID as parameter\n            - '\\TrolleyExpress 7'\n            - '\\TrolleyExpress 8'\n            - '\\TrolleyExpress 9'\n            - '\\TrolleyExpress.exe 7'\n            - '\\TrolleyExpress.exe 8'\n            - '\\TrolleyExpress.exe 9'\n      # Common dumpers\n            - '\\TrolleyExpress.exe -ma '\n    renamed:\n        Image|endswith: '\\TrolleyExpress.exe'\n    filter_renamed:\n        OriginalFileName|contains: 'CtxInstall'\n    filter_empty:\n        OriginalFileName: null\n    condition: selection or ( renamed and not 1 of filter* )\nfalsepositives:\n    - Unknown\nlevel: high\n","validation":"yaml_parsed_not_backend_compiled_or_live_validated","techniques":[{"key":"enterprise/T1003.001","id":"T1003.001","name":"LSASS Memory","page":"techniques/enterprise/T1003.001/"},{"key":"enterprise/T1218.011","id":"T1218.011","name":"Rundll32","page":"techniques/enterprise/T1218.011/"}],"data_path":"data/detection-rules/4c0aaedc-154c-4427-ada0-d80ef9c9deb6.json","kind":"sigma"}