Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 1fbf1fd019152eb3…

MALICIOUS

RTF / .DOC

21.9 KB First seen: 2022-12-02
MD5: 78b832b25636292dbe51a7848173a6c9 SHA-1: a77549afb8f9395202ef71502dd88db87afe230b SHA-256: 1fbf1fd019152eb3a1f6a460ee3252c3678d5290e3dd92e383afe6d47f4266fa
140 Risk Score

Malware Insights

MITRE ATT&CK
T1204 Malicious Link T1059 Command and Scripting Interpreter

The RTF document contains an OLE object with a split Equation Editor ProgID, indicating an attempt to exploit a known vulnerability. The presence of \objupdate and a lure to 'Enable editing' strongly suggests the document is designed to trigger an exploit, likely for downloading a second-stage payload. The document body itself is a lure, presenting academic content to mask the malicious intent.

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_off00004206.bin
89f1ec64c990dc36db29c98780371790b6510a1a405cfd15752d52ab6807706d
rtf-objdata-decoded RTF \objdata at offset 0x4206 1241 bytes