Malicious RTF — malware analysis report

Static analysis result for SHA-256 bb72ebf389705751…

MALICIOUS

RTF

14.6 KB First seen: 2018-07-08
MD5: 6ebf11a6a88bc1987f3e032de3e5395a SHA-1: 382d362aeb1e9a9db809f24c7d9a128928f87e87 SHA-256: bb72ebf389705751d507a7de6695ee1b8b86f0d3f5a166da2131c2f417f44b6d
220 Risk Score

Malware Insights

MITRE ATT&CK
T1203 Exploitation for Client Execution T1566.001 Spearphishing Attachment

The file is an RTF document that contains embedded OLE object data and specifically triggers heuristics related to the Equation Editor vulnerability (CVE-2017-11882). This vulnerability is known to allow for arbitrary code execution. The presence of `RTF_EQUATION_EDITOR` and `RTF_OBJUPDATE` heuristics strongly indicates exploitation of this CVE. The ClamAV detection name further confirms this specific exploit. The attack pattern is likely to be a spearphishing attachment leading to client execution via this exploit.

Heuristics 5

  • Equation Editor CLSID critical CVE likely RTF_EQUATION_EDITOR
    Equation Editor OLE CLSID found inside an OLE object — exploited by CVE-2017-11882 / CVE-2018-0802 / CVE-2018-0798
  • 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.
  • ClamAV: Rtf.Exploit.CVE_2017_11882-6584355-1 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Rtf.Exploit.CVE_2017_11882-6584355-1
  • \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_off000007e7.bin rtf-objdata-decoded RTF \objdata at offset 0x7E7 5235 bytes
SHA-256: e616bfb810120b79d51b6109bb93fe3d2f1241b76fdc6ce88361d3aadde8f419