Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 5ff216c904674f18…

MALICIOUS

RTF / .DOC

36.5 KB First seen: 2023-01-12
MD5: 1f9c3ebe6f934859ccf9f96dfce96430 SHA-1: 7a335fd8167282b9c50b343acae05113d7e72e33 SHA-256: 5ff216c904674f1889d5c8e02a3b764a73b066fc9480849e91f97df33401ccac
140 Risk Score

Malware Insights

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

The RTF document contains an embedded OLE object with a split Equation Editor ProgID, a known exploit technique. The \objupdate directive forces OLE activation, and the document body includes a lure instructing the user to 'Enable editing'. This combination strongly suggests an attempt to exploit the Equation Editor vulnerability to execute a malicious 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.
  • \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
  • Macro/content-enable lure medium SE_ENABLE_LURE
    Document instructs the user to enable macros or editing — a common technique used by malware droppers to bypass Office macro security settings

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
objdata_00_off00004ec8.bin
a0549c3585e490030e258f6e0f5a04e5aa4d2aeeebb3b8e279854a7ec59513ae
rtf-objdata-decoded RTF \objdata at offset 0x4EC8 1912 bytes