Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 34a8dbdc4b86c6a0…

MALICIOUS

RTF / .DOC

24.9 KB First seen: 2022-11-21
MD5: b998a564b597dea5a278b1f0a2c11b2b SHA-1: 7f61cbe7fd68882b528ce75c9f4384e50089d1b1 SHA-256: 34a8dbdc4b86c6a020c06379fa78979dabcfea78939fc48a0a9b0c471f89396a
140 Risk Score

Malware Insights

MITRE ATT&CK
T1203 Exploitation for Client Execution T1059.005 PowerShell

The sample is an RTF document containing an embedded OLE object that exploits a known vulnerability in the Microsoft Equation Editor. The presence of \objdata and \objupdate heuristics strongly suggests an attempt to trigger code execution. The document body contains a lure to enable editing, which is a common tactic for macro-based malware.

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_off000046f0.bin
158d5e0deb8b42a0c5dd47885f9c4b59b0f14a8f6d79f84d0aed78e14bc18627
rtf-objdata-decoded RTF \objdata at offset 0x46F0 1631 bytes