Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 dcc0570042581811…

MALICIOUS

RTF / .DOC

26.4 KB First seen: 2022-12-06
MD5: 6bd8344d3e2020669dd235bb644751d7 SHA-1: 40cb3aee59b4a0910647856470bf06cb1eb4dfa4 SHA-256: dcc0570042581811969853fd2e1b3c47578827602b0b56488604a6b442d92c7e
140 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious File T1059.005 Visual Basic

The sample is an RTF document containing an embedded OLE object that exploits the Equation Editor vulnerability. The ".objupdate" directive forces the activation of this OLE object, which is a known method for delivering malicious payloads. The document body contains a lure to enable editing, further supporting its role as a malicious dropper.

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_off0000455c.bin
7821667f965c25000b220435a187fc978d8c3bcaf16c056caaa57eea688c4d56
rtf-objdata-decoded RTF \objdata at offset 0x455C 1700 bytes