Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 5fdbcbea1751a796…

MALICIOUS

RTF / .DOC

9.5 KB First seen: 2022-03-03
MD5: 90fe07836c23d2fc42c84dbd485d4b5f SHA-1: a4215b4290c5b1a16015b3a904d4c84824455bb9 SHA-256: 5fdbcbea1751a7969f219297b61ed6080d0840962cd60cf99593d89448622714
120 Risk Score

Malware Insights

MITRE ATT&CK
T1203 Exploitation for Client Execution T1566.001 Spearphishing Attachment

The sample is an RTF document containing embedded OLE objects and specifically triggers heuristics for the Equation Editor vulnerability. This indicates an attempt to exploit client-side execution capabilities. The presence of \objupdate further suggests that the embedded object is designed to be activated automatically, likely to download and execute a malicious 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 2 \objdata section(s) — embedded OLE objects

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
objdata_00_off000014cd.bin
1d28d53246c10ad784f175db64b48779c5771420de353cc12e1b219e6162612a
rtf-objdata-decoded RTF \objdata at offset 0x14CD 2077 bytes