Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 861aeeadb9914b6f…

MALICIOUS

RTF / .DOC

15.1 KB First seen: 2022-10-03
MD5: 297df2bbcc2d8fc076209fb7fab6fe8a SHA-1: 3d379b9414d1c5656657bb776f402bcb38cf653d SHA-256: 861aeeadb9914b6fdb05bdc1c3dba003f2599fbd2f145cccd8954d73edba2ee4
140 Risk Score

Malware Insights

MITRE ATT&CK
T1204 Malicious Link T1566.001 Spearphishing Attachment T1059.005 Visual Basic

The sample is an RTF document that leverages OLE object data and specifically targets the Equation Editor, a known vector for exploits. The document body contains a lure instructing the user to 'Enable editing' to view the content, indicating a social engineering attempt to bypass security measures. The presence of RTF-specific heuristics like RTF_OBJDATA and RTF_EQUATION_EDITOR strongly suggests an exploit delivery mechanism.

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_off00001fa3.bin
77fc95758c0cc83d3622844c4a7911bcbefe424b465baee10c791b3a09637621
rtf-objdata-decoded RTF \objdata at offset 0x1FA3 1346 bytes