Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 120ed575fbbc691a…

MALICIOUS

RTF / .DOC

29.6 KB First seen: 2022-12-06
MD5: 43357457f8c6d490b71c157ca62dd6bd SHA-1: 1f341aafd5f24377a7a9621cb3675a87cde401e7 SHA-256: 120ed575fbbc691ab3686f423e6f0274805d17a7763b618fa507f17467c808cd
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 with a split Equation Editor ProgID, a known exploit technique. The \objupdate directive forces OLE activation, indicating an attempt to trigger the exploit. The document body contains a lure to enable editing, common for macro-based malware delivery.

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_off00004ab9.bin
f7f0b6fa779ae926dada53e0ba03e020bf877d52e14856f2008f17bac81199c2
rtf-objdata-decoded RTF \objdata at offset 0x4AB9 2037 bytes