Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 910585dc854d7d42…

MALICIOUS

RTF / .DOC

72.5 KB First seen: 2023-09-19
MD5: 3759689edfb57ad919ccef034d098474 SHA-1: 5c46f544dbe6d9d169b62e5ff3e473887c495810 SHA-256: 910585dc854d7d426da46658ef550dd9c3f2303777d94193a8e765a5f711d9ca
180 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious File T1059.005 Visual Basic

The file is an RTF document containing an embedded OLE object, specifically leveraging the Equation Editor vulnerability (T1189). The document body contains a lure to 'Enable editing' to bypass security measures. The presence of RTF_OBJAUTLINK and RTF_OBJUPDATE heuristics indicates the OLE object is designed to be automatically activated upon opening, likely to exploit the Equation Editor vulnerability and 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_off0000413d.bin
43db849a951bc46fa4cad491c77d073e53f67e99a378e76facfc33f5fc832ae2
rtf-objdata-decoded RTF \objdata at offset 0x413D 1565 bytes