Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 a8b9acee89ffa97a…

MALICIOUS

RTF / .DOC

28.3 KB First seen: 2022-11-25
MD5: 94cccbfdbdc8b3b08ae27ceae05fd95e SHA-1: 9cde8c504cb593add32b1c466c75b29407e58cd4 SHA-256: a8b9acee89ffa97a9e2cde4559523076a61fd0cabdc913746b33dc751567dd52
140 Risk Score

Malware Insights

MITRE ATT&CK
T1204 User Execution T1204.002 Malicious File T1059 Command and Scripting Interpreter

The RTF document contains an embedded OLE object with a split Equation Editor ProgID, indicating an attempt to exploit the Equation Editor vulnerability. The presence of \objupdate forces OLE activation, and the document body contains a lure instructing the user to 'Enable editing'. This combination strongly suggests the file is designed to exploit this vulnerability to execute a secondary 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.
  • \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
  • Macro/content-enable lure medium SE_ENABLE_LURE
    Document instructs the user to enable macros or editing — a common technique used by malware droppers to bypass Office macro security settings

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
objdata_00_off00005aa3.bin
7d8af6623c18b21c2e50c8c0d43a2aee0e32defe74bc89f1f8b5ff8682bef19b
rtf-objdata-decoded RTF \objdata at offset 0x5AA3 1640 bytes