Potentially Suspicious Rundll32 Activity

calendar Oct 18, 2023 · attack.defense_evasion attack.t1218.011  ·
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Detects suspicious execution of rundll32, with specific calls to some DLLs with known LOLBIN functionalities

Sigma rule (View on GitHub)

  1title: Potentially Suspicious Rundll32 Activity
  2id: e593cf51-88db-4ee1-b920-37e89012a3c9
  3status: test
  4description: Detects suspicious execution of rundll32, with specific calls to some DLLs with known LOLBIN functionalities
  5references:
  6    - http://www.hexacorn.com/blog/2017/05/01/running-programs-via-proxy-jumping-on-a-edr-bypass-trampoline/
  7    - https://twitter.com/Hexacorn/status/885258886428725250
  8    - https://gist.github.com/ryhanson/227229866af52e2d963cf941af135a52
  9    - https://twitter.com/nas_bench/status/1433344116071583746 # dfshim.dll,ShOpenVerbShortcut
 10    - https://twitter.com/eral4m/status/1479106975967240209 # scrobj.dll,GenerateTypeLib
 11    - https://twitter.com/eral4m/status/1479080793003671557 # shimgvw.dll,ImageView_Fullscreen
 12author: juju4, Jonhnathan Ribeiro, oscd.community, Nasreddine Bencherchali (Nextron Systems)
 13date: 2019/01/16
 14modified: 2023/05/17
 15tags:
 16    - attack.defense_evasion
 17    - attack.t1218.011
 18logsource:
 19    category: process_creation
 20    product: windows
 21detection:
 22    selection:
 23        - CommandLine|contains|all:
 24              - 'javascript:'
 25              - '.RegisterXLL'
 26        - CommandLine|contains|all:
 27              - 'url.dll'
 28              - 'OpenURL'
 29        - CommandLine|contains|all:
 30              - 'url.dll'
 31              - 'OpenURLA'
 32        - CommandLine|contains|all:
 33              - 'url.dll'
 34              - 'FileProtocolHandler'
 35        - CommandLine|contains|all:
 36              - 'zipfldr.dll'
 37              - 'RouteTheCall'
 38        - CommandLine|contains|all:
 39              - 'shell32.dll'
 40              - 'Control_RunDLL'
 41        - CommandLine|contains|all:
 42              - 'shell32.dll'
 43              - 'ShellExec_RunDLL'
 44        - CommandLine|contains|all:
 45              - 'mshtml.dll'
 46              - 'PrintHTML'
 47        - CommandLine|contains|all:
 48              - 'advpack.dll'
 49              - 'LaunchINFSection'
 50        - CommandLine|contains|all:
 51              - 'advpack.dll'
 52              - 'RegisterOCX'
 53        - CommandLine|contains|all:
 54              - 'ieadvpack.dll'
 55              - 'LaunchINFSection'
 56        - CommandLine|contains|all:
 57              - 'ieadvpack.dll'
 58              - 'RegisterOCX'
 59        - CommandLine|contains|all:
 60              - 'ieframe.dll'
 61              - 'OpenURL'
 62        - CommandLine|contains|all:
 63              - 'shdocvw.dll'
 64              - 'OpenURL'
 65        - CommandLine|contains|all:
 66              - 'syssetup.dll'
 67              - 'SetupInfObjectInstallAction'
 68        - CommandLine|contains|all:
 69              - 'setupapi.dll'
 70              - 'InstallHinfSection'
 71        - CommandLine|contains|all:
 72              - 'pcwutl.dll'
 73              - 'LaunchApplication'
 74        - CommandLine|contains|all:
 75              - 'dfshim.dll'
 76              - 'ShOpenVerbApplication'
 77        - CommandLine|contains|all:
 78              - 'dfshim.dll'
 79              - 'ShOpenVerbShortcut'
 80        - CommandLine|contains|all:
 81              - 'scrobj.dll'
 82              - 'GenerateTypeLib'
 83              - 'http'
 84        - CommandLine|contains|all:
 85              - 'shimgvw.dll'
 86              - 'ImageView_Fullscreen'
 87              - 'http'
 88        - CommandLine|contains|all:
 89              - 'comsvcs.dll'
 90              - 'MiniDump'
 91    filter_main_screensaver:
 92        CommandLine|contains: 'shell32.dll,Control_RunDLL desk.cpl,screensaver,@screensaver'
 93    filter_main_parent_cpl:  # Settings
 94        ParentImage: 'C:\Windows\System32\control.exe'
 95        ParentCommandLine|contains: '.cpl'
 96        CommandLine|contains|all:
 97            - 'Shell32.dll'
 98            - 'Control_RunDLL'
 99            - '.cpl'
100    filter_main_startmenu:
101        ParentImage: 'C:\Windows\System32\control.exe'
102        CommandLine|startswith: '"C:\Windows\system32\rundll32.exe" Shell32.dll,Control_RunDLL "C:\Windows\System32\'
103        CommandLine|endswith: '.cpl",'
104    condition: selection and not 1 of filter_main_*
105falsepositives:
106    - False positives depend on scripts and administrative tools used in the monitored environment
107level: medium

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