Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 f64d85c1027233b2…

MALICIOUS

RTF / .DOC

11.0 KB First seen: 2022-04-11
MD5: 247098c53b831aa01690deef74ba425b SHA-1: 9dc7bb0128d03abb3998edd1046273184e287cda SHA-256: f64d85c1027233b2f033e0cc15db20919049631a37da485b6c0f3b83149e176a
121 Risk Score

Malware Insights

MITRE ATT&CK
T1203 Exploitation for Client Execution

The sample is an RTF document containing OLE object data and specifically triggers the RTF_EQUATION_EDITOR heuristic. This indicates the exploitation of a vulnerability within the Equation Editor component. The RTF_OBJUPDATE heuristic suggests that the embedded OLE object is automatically activated upon opening the document. This combination strongly points to an exploit designed for remote code execution, likely to download and execute a further stage.

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_off00001b8c.bin
5037ff5595cc4f89a1598e6b8a1fc7ed90a20964df8fd52639b05c3933e7901a
rtf-objdata-decoded RTF \objdata at offset 0x1B8C 1942 bytes