Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 36b4be3b7fc7b062…

MALICIOUS

RTF / .DOC

21.4 KB
MD5: 1bc5fbab70dae1f3dc15c566ac313d6d SHA-1: 5e60b5825aca19c142a1dfb1712cfc8e369eae17 SHA-256: 36b4be3b7fc7b062c84ee5ebf712875ed9b53379dee13b34b50874555daf72cb
120 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious File

The sample is an RTF document containing OLE object data and triggering critical heuristics for Equation Editor exploitation. The ".objupdate" heuristic indicates that the embedded OLE object is forced to activate, which is a common technique for exploiting Equation Editor vulnerabilities. This suggests the document is designed to exploit a known vulnerability to achieve arbitrary code execution, likely for downloading and executing a secondary 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_off00000981.bin
333450851b9972b95a96002213573ea1efd4b5ee05e01b5f952bae9771982d3f
rtf-objdata-decoded RTF \objdata at offset 0x981 1963 bytes