Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 c69fa7ffcfb33582…

MALICIOUS

RTF / .DOC

22.7 KB First seen: 2022-11-25
MD5: 4a6679247f3dd4bd007b9c882dfbd3d5 SHA-1: 80eb91ad0c2a3e94bca2c36a22d7d709d19d4e72 SHA-256: c69fa7ffcfb33582d832f3cb3fbb9ec9caac55c5b70b3b4cd884aa30050970b7
140 Risk Score

Malware Insights

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

The sample is an RTF document containing an embedded OLE object, specifically targeting the Equation Editor vulnerability. The document body contains a lure instructing the user to 'Enable editing' to view its content, which is a common tactic for macro-based malware. The presence of RTF_OBJDATA, RTF_EQUATION_EDITOR, and RTF_OBJUPDATE heuristics strongly indicates exploitation of the Equation Editor via an embedded OLE object.

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_off00004595.bin
f0e078fa154765f4159cd597720147453dd443a27bc714880973b08065b657e3
rtf-objdata-decoded RTF \objdata at offset 0x4595 1503 bytes