Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 0a3c195993e2fc71…

MALICIOUS

RTF / .DOC

41.2 KB First seen: 2023-04-19
MD5: 433679b6dafda193198dd030464fcbfb SHA-1: 6c99308f23802ed7aa141e7bb9b49351e9cfcef9 SHA-256: 0a3c195993e2fc711976afcd85eaa623bc672c5945275dbd9c44b55d0930d436
180 Risk Score

Malware Insights

MITRE ATT&CK
T1204 User Execution T1204.002 Malicious File

The RTF document contains heuristics indicating the presence of an embedded OLE object, specifically targeting the Equation Editor vulnerability. The document body includes a lure instructing the user to 'Enable editing', which is a common tactic to bypass security measures and trigger the exploit. The embedded OLE object is likely designed to download and execute a secondary payload.

Heuristics 5

  • 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 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_off00004d12.bin
15be0e592b2a0805c0e301eb803d700d2afd1e919ffd291cb9d971fa949fbd1b
rtf-objdata-decoded RTF \objdata at offset 0x4D12 1700 bytes