Potential Emotet Rundll32 Execution

calendar Oct 18, 2023 · attack.defense_evasion attack.t1218.011 detection.emerging_threats  ·
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Detecting Emotet DLL loading by looking for rundll32.exe processes with command lines ending in ,RunDLL or ,Control_RunDLL

Sigma rule (View on GitHub)

 1title: Potential Emotet Rundll32 Execution
 2id: 54e57ce3-0672-46eb-a402-2c0948d5e3e9
 3status: test
 4description: Detecting Emotet DLL loading by looking for rundll32.exe processes with command lines ending in ,RunDLL or ,Control_RunDLL
 5references:
 6    - https://paste.cryptolaemus.com/emotet/2020/12/22/emotet-malware-IoCs_12-22-20.html
 7    - https://cyber.wtf/2021/11/15/guess-whos-back/
 8author: FPT.EagleEye
 9date: 2020/12/25
10modified: 2023/02/21
11tags:
12    - attack.defense_evasion
13    - attack.t1218.011
14    - detection.emerging_threats
15logsource:
16    category: process_creation
17    product: windows
18detection:
19    selection_img:
20        - Image|endswith: '\rundll32.exe'
21        - OriginalFileName: 'RUNDLL32.EXE'
22    selection_cli:
23        CommandLine|endswith:
24            - ',RunDLL'
25            - ',Control_RunDLL'
26            # - ',#1'  too generic - function load by ordinal is not Emotet specific
27    filter_legitimate_dll:
28        CommandLine|endswith:
29            - '.dll,Control_RunDLL'
30            - '.dll",Control_RunDLL'
31            - '.dll'',Control_RunDLL'
32    filter_ide:
33        ParentImage|endswith: '\tracker.exe' # When Visual Studio compile NodeJS program, it might use MSBuild to create tracker.exe and then, the tracker.exe fork rundll32.exe
34    condition: all of selection_* and not 1 of filter_*
35falsepositives:
36    - Unknown
37level: critical

References

  • Daily Emotet IoCs and Notes for 12/22/20

    Emotet Malware Document links/IOCs for 12/22/20 as of 12/23/20 01:45 EDTNotes and Credits at the bottom. Follow us on Twitter @cryptolaemus1 for more updates...


    Read More

  • Guess who’s back

    tl;dr: Emotet The (slighty) longer story:On Sunday, November 14, at around 9:26pm UTC we observed on several of our Trickbot trackers that the bot tried to download a DLL to the system. According t…


    Read More

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