Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 817ae42d463fc882…

MALICIOUS

RTF / .DOC

4.6 KB First seen: 2022-06-14
MD5: 840ab1e1101e2241ba9b96c64405c94d SHA-1: 9db121bd60246661d60a3b65355800a4c6144f66 SHA-256: 817ae42d463fc882a314134476c2132bd3cc25cc17477e444937cf8fe97774b8
120 Risk Score

Malware Insights

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

The file is an RTF document that contains embedded OLE object data, specifically targeting the Equation Editor vulnerability. The presence of RTF_OBJDATA, RTF_EQUATION_EDITOR, and RTF_OBJUPDATE heuristics indicates that the file is designed to exploit this vulnerability upon opening, likely leading to arbitrary code execution. The document body contains obfuscated data, suggesting it's not intended for direct user interaction but rather as a carrier for the exploit.

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_off00000084.bin
c83226377c4605ab1c73c69b1856de5bca06b1eb55e8e05a53189d633d90bb55
rtf-objdata-decoded RTF \objdata at offset 0x84 1919 bytes