Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 a274aac5116a0ac4…

MALICIOUS

RTF / .DOC

26.9 KB First seen: 2023-04-03
MD5: 8b33f455d3011f5b75cdf053e59ab724 SHA-1: 29c35484623d8b483e4f4e2f053b873b4d08f55c SHA-256: a274aac5116a0ac420cbef327f96663a687239d4e8668a2b89ad65b6147c8fe1
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 to bypass macro security and activate the exploit. The presence of OLE object data further supports the exploitation vector.

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_off0000483e.bin
6d2ee943c35f69347f5b87d5e8d4a45f664af19ec6e4d84e995f987977d97a94
rtf-objdata-decoded RTF \objdata at offset 0x483E 1388 bytes