sigmamediumHunting

Potentially Suspicious Regsvr32 HTTP/FTP Pattern

Detects regsvr32 execution to download/install/register new DLLs that are hosted on Web or FTP servers.

MITRE ATT&CK

defense-evasion

Detection Query

selection_img:
  - Image|endswith: \regsvr32.exe
  - OriginalFileName: REGSVR32.EXE
selection_flag:
  CommandLine|contains:
    - " /i"
    - " -i"
selection_protocol:
  CommandLine|contains:
    - ftp
    - http
condition: all of selection_*

Author

Florian Roth (Nextron Systems)

Created

2023-05-24

Data Sources

windowsProcess Creation Events

Platforms

windows

References

Tags

attack.defense-evasionattack.t1218.010

Raw Content

title: Potentially Suspicious Regsvr32 HTTP/FTP Pattern
id: 867356ee-9352-41c9-a8f2-1be690d78216
related:
    - id: 8e2b24c9-4add-46a0-b4bb-0057b4e6187d
      type: obsolete
status: test
description: Detects regsvr32 execution to download/install/register new DLLs that are hosted on Web or FTP servers.
references:
    - https://twitter.com/mrd0x/status/1461041276514623491
    - https://twitter.com/tccontre18/status/1480950986650832903
    - https://lolbas-project.github.io/lolbas/Binaries/Regsvr32/
author: Florian Roth (Nextron Systems)
date: 2023-05-24
modified: 2023-05-26
tags:
    - attack.defense-evasion
    - attack.t1218.010
logsource:
    category: process_creation
    product: windows
detection:
    selection_img:
        - Image|endswith: '\regsvr32.exe'
        - OriginalFileName: 'REGSVR32.EXE'
    selection_flag:
        CommandLine|contains:
            - ' /i'
            - ' -i'
    selection_protocol:
        CommandLine|contains:
            - 'ftp'
            - 'http'
    condition: all of selection_*
falsepositives:
    - Unknown
level: medium