Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 fe59c848486b2522…

MALICIOUS

RTF / .DOC

28.4 KB First seen: 2022-12-15
MD5: 429234c1857ddeb86662d404ba052fa4 SHA-1: 4744505923fb645922b9f41cf9472b7e5e065ffb SHA-256: fe59c848486b25227c84f9a32f8ad56e8c9ac7653975ff66495da67b995e97cd
140 Risk Score

Malware Insights

MITRE ATT&CK
T1204 Malicious Link T1059.005 PowerShell T1059.001 PowerShell T1059.003 Windows Command Shell

The sample is an RTF document that uses an Equation Editor exploit, indicated by the RTF_EQUATION_EDITOR and RTF_OBJUPDATE heuristics. It also contains a lure to enable editing, a common technique for macro-based malware droppers. The embedded OLE object data suggests it's designed to deliver a secondary payload.

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_off000056a1.bin
9c53099e6600b05cd0edfcf10572f9d8d5e491a6adb7aa61f57a203b0750ba83
rtf-objdata-decoded RTF \objdata at offset 0x56A1 1923 bytes