Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 d5b688f2bd380e9b…

MALICIOUS

RTF / .DOC

20.5 KB
MD5: 1def5d92eec091020fd68b5dd0c3bda1 SHA-1: b8def92fc99649daba1a9bd16f3ef57facd05a9c SHA-256: d5b688f2bd380e9b3c38c272f2a1de638282ef6600f3ae717d75971e2eb0dcd7
120 Risk Score

Malware Insights

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

The sample is an RTF document containing OLE object data and specifically targets the Equation Editor vulnerability. The presence of `RTF_EQUATION_EDITOR` and `RTF_OBJUPDATE` heuristics indicates an attempt to exploit this known vulnerability. The `RTF_OBJDATA` heuristic further confirms the embedding of OLE objects, which is a common delivery mechanism for exploits. The attack likely aims to achieve code execution to download and run a secondary payload.

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 2 \objdata section(s) — embedded OLE objects

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
objdata_00_off00001909.bin
ef00bc90415da79ebb7848d7f212d633f8a46c033c8ff718430f7a903a5b4119
rtf-objdata-decoded RTF \objdata at offset 0x1909 1693 bytes