Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 a21b87dee98e9551…

MALICIOUS

RTF / .DOC

29.6 KB First seen: 2022-12-19
MD5: 47c1af8dc03fcf167b2e2909fa0fecd6 SHA-1: 092c3bc0c2c5eb003acee0284131c0d2ea13f35c SHA-256: a21b87dee98e9551ca59d5532c9abfd900809a060f22e69aa62e0b493ed9b65b
140 Risk Score

Malware Insights

MITRE ATT&CK
T1204 Malicious Link T1204.002 Malicious Link: Malicious File T1059 Command and Scripting Interpreter T1059.005 Command and Scripting Interpreter: Visual Basic T1566 Phishing T1566.001 Phishing: Spearphishing Attachment

The sample is an RTF document containing an embedded OLE object that exploits a known vulnerability in the Equation Editor component of Microsoft Office. The presence of \objupdate indicates an attempt to automatically activate the embedded object upon opening. The heuristic 'SE_ENABLE_LURE' suggests the document likely contains a prompt to enable content, a common social engineering tactic to bypass security measures. The primary goal is likely to achieve code execution for a subsequent 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_off00005b22.bin
515366875a0f8e7f051deb5c223a0d9a4b634a8d30ab77442bfab24fcb8fbfd7
rtf-objdata-decoded RTF \objdata at offset 0x5B22 1516 bytes