Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 f5e9e273f0ddf60e…

MALICIOUS

RTF / .DOC

23.5 KB First seen: 2022-11-30
MD5: 3995f56cd59ae0aa4d21536b1be58f9d SHA-1: 290e2f24685cf6f572e4678b76a2713fecbe5ec3 SHA-256: f5e9e273f0ddf60e102c58bd8b5cb91f0a1eebf6b4abdca0adc8a0d3412dd48e
140 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious File T1059.005 Visual Basic

The sample is an RTF document containing an embedded OLE object with a specific Equation Editor ProgID, indicating an attempt to exploit the Equation Editor vulnerability (CVE-2017-11882). The \objupdate directive suggests the object will be activated automatically upon opening. The document also contains a lure instructing the user to 'Enable editing', a common tactic for macro-based malware.

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_off00004904.bin
97bd2d077403ea190acf2719492facb0ad0723dc434d66e35bc0d0318a9146cc
rtf-objdata-decoded RTF \objdata at offset 0x4904 1511 bytes