Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 1cc07d7f8f3031b4…

MALICIOUS

RTF / .DOC

1.88 MB First seen: 2022-03-22
MD5: 1d4606ece4cba58d6aa21f25ff3d52f2 SHA-1: ab8b62903bac5dff2f7362fb6863154c084711be SHA-256: 1cc07d7f8f3031b4d66c282c6c6874163fdb7bfdabc5ef13151bfbca060820da
300 Risk Score

Malware Insights

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

The RTF file contains multiple indicators of exploitation targeting Microsoft Equation Editor, specifically related to CVE-2018-0802. The presence of OLE object data, composite monikers, and excessive hex-encoded data within the object stream strongly suggests the embedding of a malicious payload. The ClamAV detection further confirms this, identifying it as Rtf.Exploit.CVE_2018_0802-6825822-0. This pattern is typical for delivering secondary malware through a document exploit.

Heuristics 7

  • Composite Moniker in RTF OLE object high CVE related RTF_COMPOSITE_MONIKER_RELATED
    RTF contains Composite Moniker CLSID in OLE object context, but no nearby scriptlet/SCT payload was confirmed. Treat as related moniker attack-surface evidence rather than proof of CVE-2017-8570 exploitation.
  • 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_2018_0802-6825822-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Rtf.Exploit.CVE_2018_0802-6825822-0
  • \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.
  • Large hex data blocks in OLE object high RTF_EXCESSIVE_HEX
    RTF contains ~1975KB of hex-encoded data inside \objdata sections — may hide a payload
  • 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_off000000dd.bin
adf876cc534571819fcb44ca2b118d83f78f6ec97d06f68804240cfdb4a0e14f
rtf-objdata-decoded RTF \objdata at offset 0xDD 987724 bytes