Malicious RTF — malware analysis report

Static analysis result for SHA-256 8eb67d4db341e3c1…

MALICIOUS

RTF

92.1 KB First seen: 2023-08-17
MD5: e6ec31abd924dd83e5829624c8400bfe SHA-1: 02063a4750762b451c9c7b801858ca45fb26a4aa SHA-256: 8eb67d4db341e3c1a2494e6cd111add9599850f62f65818dfd9f8f45aa49d257
180 Risk Score

Malware Insights

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

The sample is an RTF document that leverages OLE object data and specifically targets the Equation Editor, a known vector for exploits like CVE-2017-11882. The 'SE_ENABLE_LURE' heuristic indicates the document prompts the user to enable editing, a common social engineering tactic to bypass security measures. The embedded OLE object and the specific heuristics strongly suggest an attempt to exploit the Equation Editor to download and execute a malicious 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_off00002cb9.bin
5b8522559f57f0d2fbe45f9b1e7ef579d0f40a354f2a5872d19b07995118d82e
rtf-objdata-decoded RTF \objdata at offset 0x2CB9 1611 bytes