OWASSRF Exploitation Attempt Using Public POC - Webserver

calendar Feb 26, 2024 · attack.initial_access attack.t1190 detection.emerging_threats  ·
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Detects exploitation attempt of the OWASSRF variant targeting exchange servers using publicly available POC. It uses the OWA endpoint to access the powershell backend endpoint

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 1title: OWASSRF Exploitation Attempt Using Public POC - Webserver
 2id: 92d78c63-5a5c-4c40-9b60-463810ffb082
 3status: test
 4description: Detects exploitation attempt of the OWASSRF variant targeting exchange servers using publicly available POC. It uses the OWA endpoint to access the powershell backend endpoint
 5references:
 6    - https://www.crowdstrike.com/blog/owassrf-exploit-analysis-and-recommendations/
 7    - https://www.rapid7.com/blog/post/2022/12/21/cve-2022-41080-cve-2022-41082-rapid7-observed-exploitation-of-owassrf-in-exchange-for-rce/
 8    - https://twitter.com/purp1ew0lf/status/1602989967776808961?s=12&t=OkZJl_ViICeiftVEsohRyw
 9author: Nasreddine Bencherchali (Nextron Systems)
10date: 2022/12/22
11modified: 2023/01/02
12tags:
13    - attack.initial_access
14    - attack.t1190
15    - detection.emerging_threats
16logsource:
17    category: webserver
18detection:
19    selection:
20        # Look for the header: X-OWA-ExplicitLogonUser: owa/mastermailbox@outlook.com
21        cs-user-agent: 'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/105.0.5195.54 Safari/537.36'
22        cs-method: 'POST'
23        sc-status: 200
24        cs-uri-query|contains|all:
25            - '/owa/mastermailbox'
26            - '/powershell'
27    condition: selection
28falsepositives:
29    - Unlikely
30level: critical

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