Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 b3c9cce55da4ebca…

MALICIOUS

RTF / .DOC

8.6 KB First seen: 2022-04-04
MD5: 402c5e5d6b4f4e14ae9b6b1e271ddaaa SHA-1: 7ddf39e9bc511c74cc1698ae2de8ae573d7fd673 SHA-256: b3c9cce55da4ebca1733daf3d9070f275176e5edb9b4f8e5fbe48fa4411e4d10
260 Risk Score

Malware Insights

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

The file is an RTF document containing embedded OLE objects, specifically triggering critical heuristics for Equation Editor and CVE-2017-11882. This indicates the document is designed to exploit a known vulnerability in Microsoft Equation Editor to achieve arbitrary code execution upon opening. The ClamAV detection further confirms this exploit. No scripts were extracted, and the document body is minimal, providing no further context on the lure.

Heuristics 6

  • Ole10Native stream in RTF OLE object high CVE related RTF_OLE10NATIVE_STREAM
    RTF contains an embedded OLE object with an Ole10Native stream. This is a strong payload-container signal and is related to Word/OLE exploit delivery, but it is not specific enough on its own to assign a CVE.
  • 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 2 \objdata section(s) — embedded OLE objects

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
objdata_00_off00000098.bin
ce30d8ee3bac2db9b21ff4507b57faaadefce776c0919322cea846691de958bd
rtf-objdata-decoded RTF \objdata at offset 0x98 4152 bytes