Malicious RTF — malware analysis report

Static analysis result for SHA-256 a83c02d71c737e91…

MALICIOUS

RTF

9.1 KB First seen: 2019-12-09
MD5: c311483532543ad4db686cf16bc885f0 SHA-1: cd53a679dd891b8dd9b98e616af8be8564c14fc2 SHA-256: a83c02d71c737e91430a8ea666d83e0868479c345f19653bcbbac48458061450
220 Risk Score

Malware Insights

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

The RTF file contains embedded OLE object data and specifically triggers heuristics related to the Equation Editor vulnerability (CVE-2017-11882). This indicates the file is designed to exploit this vulnerability for client-side execution. The presence of OLE object activation triggers further suggests an attempt to leverage embedded objects for malicious purposes. Given the nature of the exploit, it is highly likely to have been delivered as a spearphishing attachment.

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_off0000003b.bin rtf-objdata-decoded RTF \objdata at offset 0x3B 4649 bytes
SHA-256: 22dceb4ecf1ea257aa6e75090ba9f6a952e6ac5c3a74178871915af7e80bfdcc