Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 c8811a152d66d553…

MALICIOUS

RTF / .DOC

27.8 KB First seen: 2022-12-20
MD5: 9d7259c9003643b7e9d50945fddde5f3 SHA-1: e99cd6c08439d0b0d444a900d4d4b78a8ed22ad7 SHA-256: c8811a152d66d553fe6e200afe323a4dd745a7c8a382f12fb3d720020ae2b8b4
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 specific Equation Editor ProgID, triggered by \objupdate, indicating an attempt to exploit a known vulnerability. The document body includes a lure instructing the user to 'Enable editing', a common tactic for macro-based malware droppers to bypass security settings. The presence of the OLE object and the enable editing lure strongly suggests an exploit delivery mechanism.

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_off00004e60.bin
9a9131fa77734e3cec8cfa231dcfcca6fc7a4ebdbcdb7cda04310d14d56358bd
rtf-objdata-decoded RTF \objdata at offset 0x4E60 1830 bytes