SigmaHQ/rules/web/web_exchange_proxyshell.yml
2021-08-12 10:11:17 +02:00

38 lines
1.3 KiB
YAML

title: Exchange ProxyShell Pattern
id: 23eee45e-933b-49f9-ae1b-df706d2d52ef
status: experimental
description: Detects URL patterns that could be found in ProxyShell exploitation attempts against Exchange servers (failed and successful)
references:
- https://youtu.be/5mqid-7zp8k?t=2231
- https://blog.orange.tw/2021/08/proxylogon-a-new-attack-surface-on-ms-exchange-part-1.html
- https://peterjson.medium.com/reproducing-the-proxyshell-pwn2own-exploit-49743a4ea9a1
author: Florian Roth, Rich Warren
date: 2021/08/07
modified: 2021/08/08
tags:
- attack.initial_access
logsource:
category: webserver
detection:
selection_auto:
c-uri|contains: '/autodiscover.json'
selection_uri:
c-uri|contains:
- '/powershell'
- '/mapi/nspi'
- '/EWS'
- 'X-Rps-CAT'
selection:
sc-status: 401
selection_poc:
c-uri|contains:
# since we don't know how it will appear in the log files, we'll just use all versions
- 'autodiscover.json?@'
- 'autodiscover.json%3f@'
- '%3f@foo.com'
- 'Email=autodiscover/autodiscover.json'
- 'json?@foo.com'
condition: selection_auto and selection_uri or selection_poc
falsepositives:
- Unknown
level: medium