Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 81e9b0a91e38aca2…

MALICIOUS

RTF / .DOC

3.9 KB
MD5: 62f9b4a0d977292a757f209c10d07c59 SHA-1: 2a10128913875339ce33a7790a8afc33299a651b SHA-256: 81e9b0a91e38aca2347fbd1812c95be2e04a31444629244e1f7a64b84fec45e2
160 Risk Score

Malware Insights

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

The RTF file contains an embedded OLE object that leverages the Equation Editor vulnerability (CVE-2017-11882). The presence of RTF_OBJAUTLINK and RTF_OBJUPDATE heuristics indicates that the embedded object is designed to be automatically activated upon opening the document, leading to arbitrary code execution. This is a common delivery mechanism for malware.

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 1 \objdata section(s) — embedded OLE objects

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
objdata_00_off00000066.bin
1d0d4f25cf47b0c2035a4b36f312a42a86471bdbdf5307e8cf446a7a4310655d
rtf-objdata-decoded RTF \objdata at offset 0x66 1821 bytes