Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 85c83d12212145e1…

MALICIOUS

RTF / .DOC

8.3 KB
MD5: 372c2759cee22609b6b848e74eacdbc9 SHA-1: e4e20687e2f8a8954bb11d4cdb40ce99dcb44b4d SHA-256: 85c83d12212145e186408c1910dbc95a301a13a70e37a7a32b3e14c48c8b832b
220 Risk Score

Malware Insights

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

The file is an RTF document containing an embedded OLE object that leverages the Equation Editor vulnerability (CVE-2017-11882). The presence of RTF_OBJDATA, RTF_OBJAUTLINK, and RTF_OBJUPDATE heuristics, along with the critical RTF_EQUATION_EDITOR firing, strongly indicates exploitation of this known vulnerability. The ClamAV detection further confirms its malicious nature. The embedded object is likely designed to download and execute a second-stage payload.

Heuristics 5

  • Equation Editor CLSID critical RTF_EQUATION_EDITOR
    Equation Editor OLE CLSID found inside an OLE object — exploited by CVE-2017-11882 / CVE-2018-0802 / CVE-2018-0798
  • ClamAV: Rtf.Exploit.CVE_2017_11882-6584355-1 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Rtf.Exploit.CVE_2017_11882-6584355-1
  • Automatically linked OLE object high RTF_OBJAUTLINK
    RTF contains \objautlink — an automatically linked OLE object surface that can be updated or activated when Word opens the document.
  • \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_off00000051.bin
0eb20403d7904f90350ccc887e69c07a4c727f01f56c85ee3b267abc21366f29
rtf-objdata-decoded RTF \objdata at offset 0x51 4153 bytes