Detectioncriticaltest
Certificate Request Export to Exchange Webserver
Detects a write of an Exchange CSR to an untypical directory or with aspx name suffix which can be used to place a webshell
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Max Altgelt (Nextron Systems)Created Mon Aug 23Updated Mon Jan 23b7bc7038-638b-4ffd-880c-292c692209efwindows
Log Source
Windowsmsexchange-management
ProductWindows← raw: windows
Servicemsexchange-management← raw: msexchange-management
Detection Logic
Detection Logic2 selectors
detection:
keywords_export_command:
'|all':
- 'New-ExchangeCertificate'
- ' -GenerateRequest'
- ' -BinaryEncoded'
- ' -RequestFile'
keywords_export_params:
- '\\\\localhost\\C$'
- '\\\\127.0.0.1\\C$'
- 'C:\\inetpub'
- '.aspx'
condition: keywords_export_command and keywords_export_paramsFalse Positives
Unlikely
False positives are unlikely for most environments. High confidence detection.
References
MITRE ATT&CK
Tactics
Sub-techniques
Rule Metadata
Rule ID
b7bc7038-638b-4ffd-880c-292c692209ef
Status
test
Level
critical
Type
Detection
Created
Mon Aug 23
Modified
Mon Jan 23
Path
rules/windows/builtin/msexchange/win_exchange_proxyshell_certificate_generation.yml
Raw Tags
attack.persistenceattack.t1505.003