Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 79f43ce73c2515f0…

MALICIOUS

RTF / .DOC

76.7 KB First seen: 2023-01-19
MD5: 5c07601eb21dc0c502691767598c93ef SHA-1: 940bae0047ac2b645292aebca2214b2fcaa491ad SHA-256: 79f43ce73c2515f0562cdbb96959a49ef67030b9da0f18a885f470be7a1830b7
140 Risk Score

Malware Insights

MITRE ATT&CK
T1204 User Execution: Malicious Link T1059.005 Command and Scripting Interpreter: Visual Basic

The RTF document contains an OLE object with an embedded Equation Editor ProgID, a known exploit vector. The ".objupdate" heuristic indicates that the OLE object is forced to activate, and the "SE_ENABLE_LURE" heuristic confirms the presence of a lure to enable content. This suggests the document is designed to exploit a vulnerability, likely via the Equation Editor, to execute a malicious 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_off0000414e.bin
670db599526c8c8fc51b69de277059a6bbad3a663f291cc2b857aaf3e01752e1
rtf-objdata-decoded RTF \objdata at offset 0x414E 1573 bytes