Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 9d1d0f5db3aa3591…

MALICIOUS

RTF / .DOC

16.0 KB First seen: 2023-06-14
MD5: a0056759d3d69085e2b8c67a50a03c83 SHA-1: 092deccd880a23b20d612f8b41daef61dfa96e83 SHA-256: 9d1d0f5db3aa3591c461609c50de2543621bffb461aafe0c939df74612f54102
160 Risk Score

Malware Insights

MITRE ATT&CK
T1559.001 Component Object Model T1204.002 Malicious File

The sample is an RTF document that leverages the Equation Editor vulnerability, indicated by the RTF_EQUATION_EDITOR, RTF_OBJAUTLINK, RTF_OBJUPDATE, and RTF_OBJDATA heuristic firings. This exploit likely embeds and activates an OLE object to execute a secondary payload, leading to further system compromise. The document body content is heavily obfuscated and does not provide clear instructions.

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_off00001f03.bin
2d7c0dbb4220db66756f89f849e17ff3448a2acb78db1b27d590988d95405a20
rtf-objdata-decoded RTF \objdata at offset 0x1F03 2101 bytes