Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 b753eaaa995260b5…

MALICIOUS

RTF / .DOC

9.9 KB First seen: 2022-11-02
MD5: 35a684f0dad914000450d152e3c5dd69 SHA-1: 6de36aa9b998a02a69eeeba91faa4afba6f5a413 SHA-256: b753eaaa995260b55155464f680c8244a228654d4fadfdd2b8f629e0546ee403
140 Risk Score

Malware Insights

MITRE ATT&CK
T1204 Malicious Link T1204.002 Malicious Link: Malicious File T1566 Phishing T1566.001 Phishing: Spearphishing Attachment T1059 Command and Scripting Interpreter

The file is an RTF document that utilizes an Equation Editor exploit, indicated by the RTF_EQUATION_EDITOR and RTF_OBJUPDATE heuristics. The SE_ENABLE_LURE heuristic and the document body text suggest a social engineering tactic to prompt the user to enable editing, which is a common method for macro-based malware delivery. No scripts were extracted, and the specific exploit target is not detailed, leading to an unknown family classification.

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_off000011af.bin
0e038a2401ee4af9b5f2bd00a9154b88e5bef83e4ddc01ea699adebe26948864
rtf-objdata-decoded RTF \objdata at offset 0x11AF 1409 bytes