Malicious RTF — malware analysis report

Static analysis result for SHA-256 f3954e3ea53c2527…

MALICIOUS

RTF

98.0 KB First seen: 2019-05-16
MD5: 6a2601e92a0ced6320bf92750df406c6 SHA-1: a47719f24b8f15b04cf17cf942c55ce17f5d385f SHA-256: f3954e3ea53c252718f086308392192c83e62281096319bdd904f484617e0474
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 triggers heuristics related to Equation Editor exploits, specifically CVE-2017-11882. This indicates the file is designed to exploit this vulnerability for client-side execution. The ClamAV signature further confirms the exploit. The likely goal is to download and execute a secondary payload, a common tactic for initial compromise via spearphishing attachments.

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 34822 bytes
SHA-256: 426d0b53d9d985e76b2772e38362d0f1c9843d5bc4f9655d0dc894ea2bb216a5