Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 49027f8045c58f78…

MALICIOUS

RTF / .DOC

28.3 KB First seen: 2022-11-21
MD5: 57f25e8729675674b5ab625ec3834d3f SHA-1: 8f5145873f62c713d0de7111d875dc1e0698ef0c SHA-256: 49027f8045c58f78f78ea03b02f5cbc31d64b1e76f26fa742989f8774bf1858b
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. The SE_ENABLE_LURE heuristic confirms the document instructs the user to enable editing, a common social engineering tactic. The RTF_OBJUPDATE heuristic suggests the embedded object is designed to be activated automatically. The combination of these factors points to a malicious document designed to exploit the Equation Editor vulnerability to deliver a secondary payload.

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_off00004db3.bin
6ae02ed02ac9bad8875f921e27b846a48250e6327e103e4cc4a92b7d390c4380
rtf-objdata-decoded RTF \objdata at offset 0x4DB3 2030 bytes