Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 aa92ab5924fa6110…

MALICIOUS

RTF / .DOC

41.9 KB First seen: 2023-07-18
MD5: 4bbcfab93e68c96c8d95938cf1b62a08 SHA-1: 723ce61769f9c09723ca69a58802fc1fa42ea0ae SHA-256: aa92ab5924fa611096cc9baeefd6def9e017e068f82e81ba8e65e1a49a8061d2
120 Risk Score

Malware Insights

MITRE ATT&CK
T1203 Exploitation for Client Execution

The sample is an RTF document that contains an embedded OLE object with an Equation Editor ProgID, triggering heuristics for Equation Editor exploitation. The \objupdate directive indicates that the embedded object is intended to be activated automatically, leading to code execution. The presence of objdata suggests a secondary payload is embedded or will be downloaded.

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_off00001dcc.bin
b261c8196bdde37647e0eabfcc2972218ef8e76bf3ae270356f47d475a22ed30
rtf-objdata-decoded RTF \objdata at offset 0x1DCC 10948 bytes