Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 1ea825f3f0e0d576…

MALICIOUS

RTF / .DOC

29.8 KB First seen: 2023-05-04
MD5: b4e8d27505183f3dea2f67d532451af2 SHA-1: 5b629d30ee3d6fde349ade9b80129ac288642265 SHA-256: 1ea825f3f0e0d5763da992b6f42ba33f5a475c30ce282ce24939017168bbe53a
120 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious File

The file is an RTF document that contains an embedded OLE object, triggering heuristics for Equation Editor exploitation. The `RTF_EQUATION_EDITOR` and `RTF_OBJUPDATE` firings indicate that the sample is designed to exploit a known vulnerability in the Equation Editor component to achieve arbitrary code execution. This is a common technique for delivering secondary payloads, such as malware downloaders.

Heuristics 3

  • 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

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
objdata_00_off0000539a.bin
1a20df12aa0051fcc11430fe123c421b9ae20447bac13743ef34efbaa70b2e6e
rtf-objdata-decoded RTF \objdata at offset 0x539A 1501 bytes