Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 20df06eac0646a85…

MALICIOUS

RTF / .DOC

14.7 KB First seen: 2023-02-22
MD5: 7f0575ad2474f43d494f501f380e2421 SHA-1: 4ed0e1b0bbe26e18272867ee56135d0b6db8b1a7 SHA-256: 20df06eac0646a854a74337a706c39a5583f24f6bbd1836b344f5614a46a0e92
120 Risk Score

Malware Insights

MITRE ATT&CK
T1203 Exploitation for Client Execution

The sample is an RTF document that leverages a known vulnerability in the Equation Editor component. The presence of \objdata and \objupdate heuristics strongly suggests the embedded OLE object is designed to be activated, leading to code execution. This is a common technique for delivering secondary payloads, though no specific payload or download URL was directly extracted from this sample.

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_off00001e6a.bin
ad35f5f280c7b4bb53ce81eae7703e2040a26d1291fa5bd49d3f387ca1c4be7b
rtf-objdata-decoded RTF \objdata at offset 0x1E6A 1496 bytes