Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 54c13afdad5b2420…

MALICIOUS

RTF / .DOC

22.6 KB
MD5: 5168cb1584b1bdaa02c43349a1c50cb7 SHA-1: 5fd015db6286e5ce59ab7d37afae4f921403945b SHA-256: 54c13afdad5b24209f1480db2f8243bb28e15aa0e6fb0d7b5df25422aafeaaac
160 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious File

The RTF document contains embedded OLE objects, specifically triggering heuristics related to the Equation Editor vulnerability. The presence of `RTF_EQUATION_EDITOR` and `RTF_OBJAUTLINK` strongly suggests exploitation of a known flaw in the Equation Editor component to achieve arbitrary code execution. The `RTF_OBJUPDATE` heuristic indicates that the embedded object is designed to be activated automatically upon opening the document, likely leading to the download or execution of 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_off0000162d.bin
145b9fbf599bc6c3fec0a283646a1d9e44c2e85dba9f9930319598843c447106
rtf-objdata-decoded RTF \objdata at offset 0x162D 1540 bytes