Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 c21bf0c74b53d3b4…

MALICIOUS

RTF / .DOC

4.4 KB First seen: 2022-09-15
MD5: 018292436e07423bbe0480b66bffddce SHA-1: 5bc4bca56edecea547dedfd803be36a06abd7699 SHA-256: c21bf0c74b53d3b458ba93ed8b2cd57471ef47a4d4243621756d3383664cce6e
120 Risk Score

Malware Insights

MITRE ATT&CK
T1203 Exploitation for Client Execution

The RTF file contains OLE object data and specifically triggers heuristics related to the Equation Editor vulnerability (RTF_EQUATION_EDITOR) and object activation (\\objupdate). This indicates the file is designed to exploit a known vulnerability to execute code. The presence of OLE object data suggests it's a dropper or exploit container, likely leading to a second-stage payload, though no specific script or URL was extracted to confirm the exact payload delivery mechanism.

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_off000000a6.bin
2b44758f863a267810a906ee46e7fcb675e9795b68bd937a821fd6ad872ac495
rtf-objdata-decoded RTF \objdata at offset 0xA6 1815 bytes