Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 bc0188fd8f3d27c6…

MALICIOUS

RTF / .DOC

8.2 KB First seen: 2022-03-13
MD5: 935f096d5122602a8b7f690b42c16487 SHA-1: 297703c9290a9a9c5a776cf7fe5d5dc28cbacceb SHA-256: bc0188fd8f3d27c65e38e0c750214d201621aefd80eba52187c31d7644f434b1
160 Risk Score

Malware Insights

MITRE ATT&CK
T1204 Malicious Link T1059 Command and Scripting Interpreter

The RTF document contains multiple indicators of exploitation targeting the Equation Editor component. Specifically, the presence of `RTF_EQUATION_EDITOR`, `RTF_OBJAUTLINK`, and `RTF_OBJUPDATE` heuristics strongly suggests that the document is designed to trigger an exploit. This exploit likely leads to the download and execution of a secondary payload, a common technique for initial access.

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.
  • 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 2 \objdata section(s) — embedded OLE objects

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
objdata_00_off000010e3.bin
7ce1c8cfdedf1717e2069024ecf69667c09622d3e9d4d36b58d063c64d44dd2e
rtf-objdata-decoded RTF \objdata at offset 0x10E3 1853 bytes