Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 4cf84de6af8556cc…

MALICIOUS

RTF / .DOC

150.1 KB First seen: 2022-03-15
MD5: 898bba529a26c75b6d955c8c87645712 SHA-1: 607595bd6173d0b6a3e770ee80dda0c5cabca2d4 SHA-256: 4cf84de6af8556ccb7647a48bab232b0a8eaf89b8b08973df73745d3a170d40e
135 Risk Score

Malware Insights

MITRE ATT&CK
T1203 Exploitation for Client Execution T1559.001 Component Object Model and Distributed Component Object Model

The RTF document contains embedded OLE objects, specifically triggering critical heuristics related to the Equation Editor. The presence of \objupdate indicates that the embedded OLE object is designed to be activated automatically, leading to the exploitation of a vulnerability. This strongly suggests an attack pattern focused on exploiting the Equation Editor component to achieve arbitrary code execution.

Heuristics 3

  • 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 2 \objdata section(s) — embedded OLE objects

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
objdata_00_off0000009e.bin
701b20489a0d805671dcbe49d8a544b947b6ff8238a66af8556d20c360855b5e
rtf-objdata-decoded RTF \objdata at offset 0x9E 50366 bytes