Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 6d8231884b670a4e…

MALICIOUS

RTF / .DOC

18.0 KB First seen: 2023-03-13
MD5: 1ca102c7761705407ba01d1630f1d889 SHA-1: 26c8fb559a903e60b65d308f303010265038e468 SHA-256: 6d8231884b670a4eb63ad9f3083bfa4f244d420af8146448b9101df761e4d56a
140 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious File

The file is an RTF document containing OLE object data and specifically targets the Equation Editor vulnerability. The document body includes a lure instructing the user to 'click Enable editing', which is a common tactic for macro-based malware droppers. The presence of RTF_EQUATION_EDITOR and RTF_OBJUPDATE heuristics strongly indicates an exploit attempt.

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_off00002dba.bin
0897c48626c4935aabb0d0845977b891d37a7aa983179c77feab1498f026e966
rtf-objdata-decoded RTF \objdata at offset 0x2DBA 1452 bytes