Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 791323da206a57c0…

MALICIOUS

RTF / .DOC

26.7 KB First seen: 2023-05-02
MD5: 3317f716392e2abd3fa735b6f08e6706 SHA-1: 75139a245283f184a21ef20919e706c32279ee0b SHA-256: 791323da206a57c0ad79545cbbed9f97b0979d578689982a5b2ce6f2ec7d0534
180 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 leverages the Equation Editor vulnerability (CVE-2017-11882) to execute arbitrary code. The presence of OLE object data and automatic linking suggests an attempt to trigger an exploit. The 'SE_ENABLE_LURE' heuristic indicates the document likely contains a prompt to enable content, a common tactic for macro-based malware delivery.

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_off00004445.bin
f99fff185d14228092d78a1503016ec01afedf2801a65642adfaad11d182af1d
rtf-objdata-decoded RTF \objdata at offset 0x4445 1660 bytes