Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 9a36cc9f979c4dc9…

MALICIOUS

RTF / .DOC

84.8 KB
MD5: 5162cede203b1861e5a6164b487c35dd SHA-1: dc0fa547a2729470a8fe903c5420f2166eb4ec4b SHA-256: 9a36cc9f979c4dc902f1bd8b13e2a5159b4edbc75ed4e9f909b0b6e897061981
160 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious File T1059.003 Windows Command Shell

The RTF document contains multiple indicators of exploiting the Equation Editor vulnerability, including OLE object data and automatic linking, which are known to be used for arbitrary code execution. The presence of ".objupdate" further suggests that the embedded OLE object is designed to be activated automatically upon opening the document, likely leading to the execution of a malicious payload.

Heuristics 4

  • 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.
  • Automatically linked OLE object high RTF_OBJAUTLINK
    RTF contains \objautlink — an automatically linked OLE object surface that can be updated or activated when Word opens the document.
  • \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_off00000057.bin
c2e0623d8e47a4f2f3d5a29319384b5f53e187ee475133647983576e9477dbb4
rtf-objdata-decoded RTF \objdata at offset 0x57 24051 bytes