Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 09e8530ee34bbf8a…

MALICIOUS

RTF / .DOC

58.5 KB First seen: 2023-02-07
MD5: 99ab551c6192ceb58cea0bac7f4ac455 SHA-1: 856f1b0f87aec5414c0636f07a9d67870b9e4652 SHA-256: 09e8530ee34bbf8a56ac3d8e688a5c8d79d28ada9eb9a5253dd57416322011ce
180 Risk Score

Malware Insights

MITRE ATT&CK
T1204 User Execution T1204.002 User Execution: Malicious File T1059 Command and Scripting Interpreter T1059.005 Command and Scripting Interpreter: Visual Basic

The sample is an RTF document that exploits the CVE-2017-11882 vulnerability in Microsoft Equation Editor. It contains OLE object data and is configured to automatically update and activate, indicating an attempt to execute arbitrary code. The document body includes a lure to enable editing and content, a common tactic for macro-based malware.

Heuristics 5

  • CVE-2017-11882 — Equation Editor FONT record overflow critical CVE likely CVE_2017_11882
    Equation Editor MTEF contains an overlong FONT typeface field, the vulnerable copy primitive for CVE-2017-11882. This is stronger evidence than the Equation Editor CLSID alone because it identifies the malformed record that drives code execution in EQNEDT32.EXE.
  • 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_off00000773.bin
a5e160efd354fba5889850388932a195f8aa4807582ed65e83c1f60a3c6f8c2a
rtf-objdata-decoded RTF \objdata at offset 0x773 4161 bytes