Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 afb825e21ea13b88…

MALICIOUS

RTF / .DOC

30.4 KB First seen: 2023-04-28
MD5: 1622ad39304774c31c8e8522f84e0b3d SHA-1: 1ba13ad06e2a3acfbebabdcc2886f4a43c5f6cc3 SHA-256: afb825e21ea13b8819900f09bf4bde473070230e3564f3e7ee5a49cb35a0b610
180 Risk Score

Malware Insights

MITRE ATT&CK
T1204 User Execution: Malicious Link T1059.005 Command and Scripting Interpreter: Visual Basic T1559.001 Component Object Model Hijacking

The RTF document contains an embedded OLE object with a split Equation Editor ProgID, a known technique for exploiting Equation Editor vulnerabilities. The document body presents a plausible lure, an academic assignment, instructing the user to 'Enable editing' to bypass security measures. This combination strongly suggests an attempt to exploit the Equation Editor vulnerability to execute a malicious payload.

Heuristics 5

  • Split hex Equation Editor ProgID + OLE object critical RTF_EQUATION_EDITOR
    RTF embeds the Equation.3 ProgID as hex bytes near OLE object activation and splits the byte stream with whitespace or an ignorable RTF group. This is an Equation Editor OLE activation surface commonly used by CVE-2017-11882 / CVE-2018-0802 exploit documents.
  • Automatically linked OLE object high RTF_OBJAUTLINK
    RTF contains \objautlink — an automatically linked OLE object surface that can be updated or activated when Word opens the document.
  • \objupdate forces OLE activation high RTF_OBJUPDATE
    RTF contains \objupdate — forces automatic OLE object instantiation when the document is opened, bypassing user interaction. Almost exclusively seen in Equation Editor exploit documents.
  • OLE object data medium RTF_OBJDATA
    RTF contains 1 \objdata section(s) — embedded OLE objects
  • Macro/content-enable lure medium SE_ENABLE_LURE
    Document instructs the user to enable macros or editing — a common technique used by malware droppers to bypass Office macro security settings

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
objdata_00_off000051fd.bin
2e2899089fe61539d5cc8e821216ee2d8f631beb08c33c031a9069cf2bcb50d2
rtf-objdata-decoded RTF \objdata at offset 0x51FD 1694 bytes