Malicious RTF — malware analysis report

Static analysis result for SHA-256 3ea0415e7a5af081…

MALICIOUS

RTF

9.1 KB First seen: 2019-01-20
MD5: 718783b996f42628536d7c7361136e28 SHA-1: 455bf8615efad38f2cece5337d077e645d788adf SHA-256: 3ea0415e7a5af081d4ec8338ed3091519aecafd59838b71baf47e6c743406d64
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 vulnerability allows for the execution of arbitrary code when the document is opened. The presence of ".objupdate" further indicates an attempt to activate the embedded object, likely to trigger the exploit. The file is classified as malicious due to 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_off0000003b.bin rtf-objdata-decoded RTF \objdata at offset 0x3B 4643 bytes
SHA-256: f5eae9a84acc9d5e2b304d5efbc2da96b4f59b842aaf41bd83e4356c6355f3c4