{"id":"7280c9f3-a5af-45d0-916a-bc01cb4151c9","title":"Suspicious MSExchangeMailboxReplication ASPX Write","description":"Detects suspicious activity in which the MSExchangeMailboxReplication process writes .asp and .apsx files to disk, which could be a sign of ProxyShell exploitation","author":"Florian Roth (Nextron Systems)","status":"test","level":"high","date":"2022-02-25","modified":"","tags":["attack.initial-access","attack.t1190","attack.persistence","attack.t1505.003"],"technique_ids":["T1190","T1505.003"],"logsource":{"product":"windows","category":"file_event"},"falsepositives":["Unknown"],"references":["https://redcanary.com/blog/blackbyte-ransomware/"],"source_path":"rules/windows/file/file_event/file_event_win_susp_exchange_aspx_write.yml","source_sha256":"588911a89962fc565bbda7631c23cdd2411a913caebbb4554399889232c59016","source_url":"https://github.com/anpa1200/sigma/blob/b249e9683190cffdcaf188ccbfb90bf4759844e1/rules/windows/file/file_event/file_event_win_susp_exchange_aspx_write.yml","license":"Detection Rule License 1.1","license_url":"https://github.com/SigmaHQ/Detection-Rule-License/blob/main/LICENSE.Detection.Rules.md","yaml":"title: Suspicious MSExchangeMailboxReplication ASPX Write\nid: 7280c9f3-a5af-45d0-916a-bc01cb4151c9\nstatus: test\ndescription: Detects suspicious activity in which the MSExchangeMailboxReplication process writes .asp and .apsx files to disk, which could be a sign of ProxyShell exploitation\nreferences:\n    - https://redcanary.com/blog/blackbyte-ransomware/\nauthor: Florian Roth (Nextron Systems)\ndate: 2022-02-25\ntags:\n    - attack.initial-access\n    - attack.t1190\n    - attack.persistence\n    - attack.t1505.003\nlogsource:\n    product: windows\n    category: file_event\ndetection:\n    selection:\n        Image|endswith: '\\MSExchangeMailboxReplication.exe'\n        TargetFilename|endswith:\n            - '.aspx'\n            - '.asp'\n    condition: selection\nfalsepositives:\n    - Unknown\nlevel: high\n","validation":"yaml_parsed_not_backend_compiled_or_live_validated","techniques":[{"key":"enterprise/T1190","id":"T1190","name":"Exploit Public-Facing Application","page":"techniques/enterprise/T1190/"},{"key":"enterprise/T1505.003","id":"T1505.003","name":"Web Shell","page":"techniques/enterprise/T1505.003/"}],"data_path":"data/detection-rules/7280c9f3-a5af-45d0-916a-bc01cb4151c9.json","kind":"sigma"}