Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 333a4f5801ceb9ba…

MALICIOUS

RTF / .DOC

82.1 KB
MD5: 7173396e4b9f015e40906d45a4e299b3 SHA-1: 2d66f6d42075038a236910beb96a88b921d576a2 SHA-256: 333a4f5801ceb9ba48d7bbbc0c3b1c1cc3855463182c902140129bc6ea26e716
160 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious File T1059.003 Windows Command Shell

The RTF document contains embedded OLE objects, specifically triggering the RTF_EQUATION_EDITOR heuristic. This indicates the use of a known vulnerability in Microsoft Equation Editor, likely to achieve arbitrary code execution. The presence of extasciitilde{}objupdate suggests that the embedded object is designed to be activated automatically upon opening the document, facilitating the exploitation process.

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.
  • 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 2 \objdata section(s) — embedded OLE objects

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
objdata_00_off000015d6.bin
8c2f23cd6f6f12abc664b04bfacadc529d264119f79cf48bab069510c873d8b1
rtf-objdata-decoded RTF \objdata at offset 0x15D6 1790 bytes