Malicious RTF — malware analysis report

Static analysis result for SHA-256 e846f22846f12376…

MALICIOUS

RTF

105.8 KB First seen: 2024-09-04
MD5: 41476796ffd040d708d816def202e4c0 SHA-1: b3a2d91a700ea62f63cf3121121a11de32016096 SHA-256: e846f22846f123764cf047793687eafac5ddd09ea4e0270c027c3da3e2adc06b
160 Risk Score

Malware Insights

MITRE ATT&CK
T1203 Exploitation for Client Execution T1105 Ingress Tool Transfer

The RTF file contains critical heuristics indicating exploitation of the Equation Editor vulnerability (RTF_EQUATION_EDITOR). The presence of OLE object data and automatic linking ( RTF_OBJAUTLINK, RTF_OBJUPDATE) further supports this, suggesting the file is designed to trigger code execution upon opening. The embedded OLE object likely contains a payload that downloads and executes additional malware, consistent with an initial access or downloader stage.

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 1 \objdata section(s) — embedded OLE objects

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
objdata_00_off00001ff3.bin
86f415acf875a0b2931597ee3b1a3aa363f29a6145dde0de6935638ac9efe919
rtf-objdata-decoded RTF \objdata at offset 0x1FF3 2089 bytes