Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 3d1db76ffd16afd7…

MALICIOUS

RTF / .DOC

23.5 KB First seen: 2022-11-10
MD5: 57d657b58f598801155c8e61a9993e56 SHA-1: 8287e946e24b214db4c8daf56c7d118a0d48a5e9 SHA-256: 3d1db76ffd16afd7d0513639949f0b0f1a3f4106b88bb6235664e542791fc57f
140 Risk Score

Malware Insights

MITRE ATT&CK
T1204 User Execution T1059.005 Visual Basic

The sample is an RTF document containing an embedded OLE object with a specific Equation Editor ProgID, indicating an attempt to exploit vulnerabilities like CVE-2017-11882. The document body includes a lure instructing the user to 'Enable editing' to view the content, a common tactic for macro-based malware delivery. The presence of ` tfobjdata` and ` tfobjupdate` further supports the exploitation of embedded objects.

Heuristics 4

  • 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.
  • \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_off00004740.bin
becf6850c2913a8918b2e86f4159206c50c4081b80682403fc4a0073bdf9fc0e
rtf-objdata-decoded RTF \objdata at offset 0x4740 1664 bytes