Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 e710a319c64ce4fa…

MALICIOUS

RTF / .DOC

139.7 KB First seen: 2023-07-05
MD5: bc0afa18a6a091e8114f91ac046ca4ae SHA-1: 38b2991fe27e50a799125a2140125604d25652c6 SHA-256: e710a319c64ce4faf4f267cbe40505c2a5c86d727a854d5df0c59fd13840fc5c
120 Risk Score

Malware Insights

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

The sample is an RTF document that contains OLE object data and specifically triggers heuristics related to the Equation Editor vulnerability (CVE-2017-11882). The presence of \objupdate indicates that the embedded OLE object is designed to be activated automatically, leading to the execution of malicious code. This strongly suggests a spearphishing attachment designed to exploit this known vulnerability for initial code execution.

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_off0000150e.bin
61d2eaf214b8efd8e98d6453bfe6099dbe3b48c9f8fe01de903c34b5a8556ee0
rtf-objdata-decoded RTF \objdata at offset 0x150E 43668 bytes