Malicious RTF — malware analysis report

Static analysis result for SHA-256 8928097a04660fb9…

MALICIOUS

RTF

31.6 KB First seen: 2023-07-18
MD5: 7c026b1f4922240045942711708456f1 SHA-1: ab4fb97be2b8eb89699993a06f08e0ce13d17dd8 SHA-256: 8928097a04660fb9456f7d2636b848111d5ec160dbdccf57204e09ef704a09a9
180 Risk Score

Malware Insights

MITRE ATT&CK
T1204 User Execution T1204.002 Malicious File T1059 Command and Scripting Interpreter T1059.005 Visual Basic

The RTF document contains an embedded OLE object that exploits a known vulnerability in the Microsoft Equation Editor. The document body includes a lure instructing the user to 'Enable editing' to view the content, which is a common technique to bypass macro security settings. The exploitation of the Equation Editor likely leads to the execution of a second-stage payload.

Heuristics 5

  • 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.
  • Automatically linked OLE object high RTF_OBJAUTLINK
    RTF contains \objautlink — an automatically linked OLE object surface that can be updated or activated when Word opens the document.
  • \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_off0000409b.bin
1f0e320247b157b312167bf635a0d8641e560cc86e757acdb24841a663638b04
rtf-objdata-decoded RTF \objdata at offset 0x409B 1279 bytes