Change User Agents with WebRequest

 1title: Change User Agents with WebRequest
 2id: d4488827-73af-4f8d-9244-7b7662ef046e
 3status: test
 4description: |
 5    Adversaries may communicate using application layer protocols associated with web traffic to avoid detection/network filtering by blending in with existing traffic.
 6    Commands to the remote system, and often the results of those commands, will be embedded within the protocol traffic between the client and server.    
 7references:
 8    - https://github.com/redcanaryco/atomic-red-team/blob/f339e7da7d05f6057fdfcdd3742bfcf365fee2a9/atomics/T1071.001/T1071.001.md#t1071001---web-protocols
 9author: frack113
10date: 2022-01-23
11modified: 2025-07-18
12tags:
13    - attack.command-and-control
14    - attack.t1071.001
15logsource:
16    product: windows
17    category: ps_script
18    definition: 'Requirements: Script Block Logging must be enabled'
19detection:
20    selection_webrequest:
21        ScriptBlockText|contains:
22            - 'Invoke-WebRequest'
23            - 'Invoke-RestMethod'
24            - ' irm ' # Space before and after to avoid false positives with 'irm' as a variable
25            - 'iwr '
26    selection_useragent:
27        ScriptBlockText|contains: '-UserAgent '
28    condition: all of selection_*
29falsepositives:
30    - Unknown
31level: medium