Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 bae79b629c06453b…

MALICIOUS

RTF / .DOC

41.1 KB First seen: 2023-02-07
MD5: 2a5ab8de43e107a3dcfbcdaf9d7822e9 SHA-1: fa206129c276001aec693f19853b2aeb12bff66d SHA-256: bae79b629c06453b7f34ef8786f7759bb7a891f0447aadb08ed6136648d6d815
140 Risk Score

Malware Insights

MITRE ATT&CK
T1204 Malicious Link T1059.005 Visual Basic

The RTF document contains an embedded OLE object with a split Equation Editor ProgID, indicating an attempt to exploit the Equation Editor vulnerability (CVE-2017-11882). The presence of \objupdate suggests that the embedded object is designed to be activated automatically upon opening the document. The 'SE_ENABLE_LURE' heuristic confirms that the document instructs the user to enable editing, a common social engineering tactic to bypass security measures and trigger the exploit.

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_off000057d7.bin
787bd328eef10f33432a5a35384175f9fe6bbf8eba1018928952f3cdad216d37
rtf-objdata-decoded RTF \objdata at offset 0x57D7 1830 bytes