Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 544eb0f9b455afd8…

MALICIOUS

RTF / .DOC

25.5 KB
MD5: 335e1a129ad71cecaf5c7f21304fc76f SHA-1: 8dc95389d408f8384c9461d1a63ad2b632eb6a66 SHA-256: 544eb0f9b455afd862c4ea6ca49b73c8c13b027617542cf5af83840c61960147
160 Risk Score

Malware Insights

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

The file is an RTF document containing embedded OLE objects, specifically triggering critical heuristics related to Equation Editor vulnerabilities. The presence of \objupdate indicates that the OLE object is designed to be activated automatically upon opening, likely leading to the exploitation of a known Equation Editor flaw. This pattern is commonly used to deliver a secondary payload.

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_off00000233.bin
66618b8642a1a0bc35ed622865389914df0900a466c0094ca0c882af5c173481
rtf-objdata-decoded RTF \objdata at offset 0x233 1327 bytes