Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 cc6252f22b016cf8…

MALICIOUS

RTF / .DOC

34.1 KB
MD5: 4421e4f6e4279d2c9de9c372725877ac SHA-1: 235a2f5818a48ce4a56d80882c8855dcb654f174 SHA-256: cc6252f22b016cf867546f9b2a454eea195fadb89a4de124be9b6a164271584e
160 Risk Score

Malware Insights

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

The RTF document contains embedded OLE objects, specifically triggering heuristics related to the Equation Editor vulnerability. The presence of `RTF_EQUATION_EDITOR` and `RTF_OBJAUTLINK` strongly suggests exploitation of a known flaw in the Equation Editor component to achieve arbitrary code execution upon opening the document. The `RTF_OBJUPDATE` heuristic indicates that the embedded object is designed to be activated automatically, facilitating the exploit.

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 2 \objdata section(s) — embedded OLE objects

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
objdata_00_off00000ea5.bin
6a881636de0bc0ce1c56b7a90a1f438f80942249f9627b3c80d44e56ab0650e6
rtf-objdata-decoded RTF \objdata at offset 0xEA5 1923 bytes