Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 87f90f96fad35e92…

MALICIOUS

RTF / .DOC

26.4 KB First seen: 2023-01-24
MD5: c898d4c06e6b5c512837df2d7adf1e99 SHA-1: ff1047a48cbb5f09d10e069a8ef5b0013f260948 SHA-256: 87f90f96fad35e9274e5007173c8f48e34344b1e565d3990fd4cc212fd9a2ad3
140 Risk Score

Malware Insights

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

The sample is an RTF document containing an embedded OLE object, specifically targeting the Equation Editor vulnerability. The document body includes a lure instructing the user to 'Enable editing', which is a common technique to bypass macro security settings and trigger the exploit. The presence of RTF_OBJDATA and RTF_OBJUPDATE heuristics further supports the exploitation of OLE object activation for malicious purposes.

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_off000053d1.bin
6e5f64c8adf66e1c86386dbbaf35aa228b6386a1755e2808e18c0c3352895635
rtf-objdata-decoded RTF \objdata at offset 0x53D1 1559 bytes