Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 28807be0d5215b9d…

MALICIOUS

RTF / .DOC

18.7 KB First seen: 2023-03-15
MD5: 39e1e4e78f938f3566d8c4cbcd0bb98b SHA-1: f60c12012360f6be362fb5118d3031550d260e2b SHA-256: 28807be0d5215b9d765a11cae7bf8c9e61f4e8c311aa3f7442cb67100d1e0572
140 Risk Score

Malware Insights

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

The sample is an RTF document that uses an OLE object and specifically targets the Microsoft Equation Editor, a known vector for exploits. The document body contains a lure instructing the user to 'click Enable editing', which is a common tactic to bypass macro security settings and trigger the embedded exploit. The presence of RTF_OBJDATA and RTF_OBJUPDATE heuristics further supports the exploitation of OLE objects within the RTF structure.

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_off00002e37.bin
8a3c053b8e566cfcb0846b9d8f2b962b462c2ee94d157a042ee18112e46a394f
rtf-objdata-decoded RTF \objdata at offset 0x2E37 1601 bytes