Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 fc26da679f0b6faf…

MALICIOUS

RTF / .DOC

36.7 KB First seen: 2023-07-04
MD5: 0fe0e7f7498902137e1e68201aafc3e3 SHA-1: 1cd8a00e42a9da249c730181cce114b570e7dd6f SHA-256: fc26da679f0b6fafd8c0be1c1daf867eba2e3b8f3cc2503374d332792b7efe39
140 Risk Score

Malware Insights

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

The file is an RTF document that contains embedded OLE object data, specifically targeting the Equation Editor. The presence of \objupdate indicates an attempt to force OLE activation, and the document body contains a lure instructing the user to 'Enable editing'. This combination strongly suggests an exploit targeting the Equation Editor to achieve initial execution.

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_off00004c7e.bin
3c55fa61acce2c602b30f2686a0bfe33b5db5686dbaffe190d50c51a5a3fd7df
rtf-objdata-decoded RTF \objdata at offset 0x4C7E 1876 bytes