Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 40183148f5284048…

MALICIOUS

RTF / .DOC

24.3 KB First seen: 2023-10-22
MD5: 6189e07be41e4acb4e94dea3d149f7b2 SHA-1: 384fa2a4d8e020feb1d148c884a5c77e0415c595 SHA-256: 40183148f52840484b1f6c2530b244957bef6b2c493109b52ff1b9e9e41eccde
120 Risk Score

Malware Insights

MITRE ATT&CK
T1203 Exploitation for Client Execution T1059.001 PowerShell

The sample is an RTF document containing OLE object data and specifically targets the Equation Editor vulnerability. The presence of \objupdate indicates that the embedded OLE object is designed to be activated automatically, leading to code execution. The objdata artifact is the most concrete IOC, likely containing the exploit or payload.

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 1 \objdata section(s) — embedded OLE objects

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
objdata_00_off00000da5.bin
32d4c75831fc9baa27a18a613b31834e86a82a0dc1b35a178cde8b49b43e6bb6
rtf-objdata-decoded RTF \objdata at offset 0xDA5 1708 bytes