Malicious RTF — malware analysis report

Static analysis result for SHA-256 63d1fbc91e3e0cb8…

MALICIOUS

RTF

5.6 KB First seen: 2018-11-05
MD5: 1bf5d7eabc388a3c36a45f638c923a98 SHA-1: 12e76f6e9cd085e5a680ca9a318645568f80950a SHA-256: 63d1fbc91e3e0cb8207afd43ca7f1f47336b0f10140404189eb8d2d849598f4a
222 Risk Score

Malware Insights

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

The RTF file contains an OLE object that is automatically linked and updated, exploiting CVE-2017-0199. This exploit is designed to download and execute a secondary payload from the embedded URL http://172.31.131.78:8080/default.hta. The ClamAV detection further confirms the malicious nature of this exploit.

Heuristics 6

  • CVE-2017-0199 (OLE2Link / weaponized URL) critical CVE exact CVE_2017_0199_WEAPONIZED_URL
    RTF contains a URL Moniker OLE link to a script/HTA/template-style remote loader, matching the tighter static CVE-2017-0199 shape.
  • ClamAV: Rtf.Exploit.CVE_2017_0199-6335035-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Rtf.Exploit.CVE_2017_0199-6335035-0
  • Automatically linked OLE object high RTF_OBJAUTLINK
    RTF contains \objautlink — an automatically linked OLE object surface that can be updated or activated when Word opens the document.
  • \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
  • Embedded URL info EMBEDDED_URL
    One or more URLs were extracted from the document. The URL itself is not a detection — see the per-URL labels for which channel (macro, JS, link annotation, document body, ...) reached each URL.
    URL http://172.31.131.78:8080/default.hta In RTF body
    • http://schemas.microsoft.com/office/word/2003/wordmlIn RTF body

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
objdata_00_off000001b4.bin rtf-objdata-decoded RTF \objdata at offset 0x1B4 2601 bytes
SHA-256: 101a6c4ea301a80f603b29be2a6b3ba8e83030b5254d288c27000cf47b7143a3