Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 dc41843c25553d4c…

MALICIOUS

RTF / .DOC

115.7 KB First seen: 2023-06-16
MD5: fc7bf4d38953563710c9bf4c8a22a313 SHA-1: 905a719f95e770960376b77ddb3eb567aff9d5dc SHA-256: dc41843c25553d4c3ad3666eadcab424fda983d03f756c9b4830adff4dc0c813
120 Risk Score

Malware Insights

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

The sample is an RTF document that contains OLE object data and triggers heuristics related to Equation Editor exploitation and OLE object activation. This indicates the file is designed to exploit a vulnerability, likely CVE-2017-11882, to execute code. The primary goal appears to be the download and execution of a secondary payload, as suggested by the critical Equation Editor heuristic.

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_off00001234.bin
d51e209be7973e32327c4b392917e5851f5b0631d12d44d7e700a0ba3eda8191
rtf-objdata-decoded RTF \objdata at offset 0x1234 35048 bytes