Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 63aa1d43aca07765…

MALICIOUS

RTF / .DOC

42.1 KB
MD5: c5afa9bd64dc98d2d0cdc2901977d8aa SHA-1: 6aaf581d11f67492e8d93bfcb2b1ac21da601ba6 SHA-256: 63aa1d43aca077653da63deaa833ef993415b5d55ccd162ec9b85d9807dc5049
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, specifically triggering heuristics for the Equation Editor vulnerability. The \objupdate directive indicates an attempt to automatically activate the embedded object, which is a common technique for exploiting this vulnerability to achieve code execution. The presence of OLE object data further supports this attack vector.

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_off00001c27.bin
696f45218e84292e481f8296a474dae72ce2fe08de6ce7dbbdfbfdac98276fbf
rtf-objdata-decoded RTF \objdata at offset 0x1C27 1788 bytes