Malicious RTF — malware analysis report

Static analysis result for SHA-256 3b0eecc6b2ac402c…

MALICIOUS

RTF

3.7 KB First seen: 2023-01-17
MD5: ae9601fe7ce10f0dfb10c0078241b497 SHA-1: fff7c767c88a4ee35bb9676212a9e2051b991ac4 SHA-256: 3b0eecc6b2ac402cf5d95017986a05240990a55813820d12faaf3ba2f2020f37
220 Risk Score

Malware Insights

MITRE ATT&CK
T1204 User Execution: Malicious Link T1059 Command and Scripting Interpreter

The RTF document contains an OLE object with an obfuscated Equation Editor ProgID, strongly indicating exploitation of CVE-2017-11882. The document body contains a lure in Spanish instructing the user to enable editing, which is a common technique for macro-based malware droppers to bypass security settings and trigger the exploit.

Heuristics 6

  • Obfuscated Equation Editor ProgID + activation critical CVE related RTF_EQUATION_EDITOR
    RTF decodes to an Equation.3 ProgID from top-level \objdata hex after nested RTF junk groups are ignored, and the document also contains \objemb plus \objupdate activation. This is an obfuscated Equation Editor exploit surface associated with CVE-2017-11882 / CVE-2018-0802 families, but no exact malformed MTEF CVE primitive was recovered from this object.
  • Equation Editor activation — CVE-2017-11882 related high CVE related CVE_2017_11882_ACTIVATION_RELATED
    RTF decodes to an Equation.3 ProgID and requests OLE activation with \objemb plus \objupdate. This reaches the legacy Equation Editor attack surface used by CVE-2017-11882/CVE-2018-0802 documents, but the malformed MTEF/native payload needed for stronger attribution was not recovered.
  • 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_off000000e8.bin
23e2c74cc1788fe6a65a7561f83a849f71e561a7b901f5a18c1f47dc392b0376		 rtf-objdata-decoded RTF \objdata at offset 0xE8 1744 bytes

Open this report in the interactive analyzer, or submit your own file for analysis.