Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 4610cb0b82c1f82c…

MALICIOUS

RTF / .DOC

39.9 KB First seen: 2023-04-25
MD5: 15ab40c00a4c0722e193e044ffd6a9a2 SHA-1: 2a138f2786611a3640ddd5dd704a3f53b858ba9e SHA-256: 4610cb0b82c1f82ce2dcd39bef0102534b0e459726262c9e0198bc29b888b29a
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

The sample is an RTF document that contains an embedded OLE object, specifically targeting the Equation Editor vulnerability. The document includes a lure instructing the user to 'enable editing', which is a common tactic to bypass macro security and trigger the exploit. The exploitation of the Equation Editor likely leads to the execution of a secondary 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_off0000355c.bin
7174825fb71e8eede1a672b8ebef5ef67096df252231b32c73968dcbc2911134
rtf-objdata-decoded RTF \objdata at offset 0x355C 1982 bytes