Malicious RTF — malware analysis report

Static analysis result for SHA-256 a8070ffcc056c034…

MALICIOUS

RTF

1.86 MB First seen: 2019-11-20
MD5: 9a9f8d06e2758213deace4af22af83c0 SHA-1: c0958f651bac4f8ca648e255a9f931545c681496 SHA-256: a8070ffcc056c034d71350b3ffc95cdd78812d3f9a8b0d5ac4e4db0af21e9028
224 Risk Score

Malware Insights

MITRE ATT&CK
T1203 Exploitation for Client Execution

The RTF file contains multiple indicators of malicious activity, including OLE object data and excessive hex data, strongly suggesting the presence of a hidden payload. The critical heuristic firing for CVE-2017-8570 indicates the file is designed to drop an SCT script. The embedded URL http://test1.ru/newbuild/t.php?act=hit is likely involved in the payload delivery chain.

Heuristics 8

  • Composite Moniker — CVE-2017-8570 (drops SCT script) critical CVE related CVE_2017_8570
    RTF \objdata decodes to OLE data containing the Composite Moniker — CVE-2017-8570 (drops SCT script) CLSID — the vulnerable control/moniker is embedded directly in the document's object stream, the delivery shape of this exploit. RTF objects auto-render when Word opens the file.
  • Composite Moniker in RTF OLE object high CVE related RTF_COMPOSITE_MONIKER_RELATED
    RTF contains Composite Moniker CLSID in OLE object context, but no nearby scriptlet/SCT payload was confirmed. Treat as related moniker attack-surface evidence rather than proof of CVE-2017-8570 exploitation.
  • \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.
  • Large hex data blocks in OLE object high RTF_EXCESSIVE_HEX
    RTF contains ~1766KB of hex-encoded data inside \objdata sections — may hide a payload
  • OLE object data medium RTF_OBJDATA
    RTF contains 7 \objdata section(s) — embedded OLE objects
  • Embedded OLE object medium RTF_OBJEMB
    RTF contains \objemb — embedded OLE object
  • Suspicious extracted artifact info EXTRACTED_FILE_STATIC_TRIAGE
    One or more files extracted from inside this sample matched static suspicious-content checks such as script obfuscation, encoded payload blobs, packed data, or execution/download terms.
  • 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://test1.ru/newbuild/t.php?act=hit In RTF body
    • http://ns.adobe.com/xap/1.0/In RTF body
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In RTF body
    • http://ns.adobe.com/photoshop/1.0/In RTF body
    • http://ns.adobe.com/xap/1.0/mm/In RTF body
    • http://ns.adobe.com/xap/1.0/sType/ResourceRef#In RTF body
    • http://ns.adobe.com/xap/1.0/sType/ResourceEvent#In RTF body
    • http://purl.org/dc/elements/1.1/In RTF body
    • http://ns.adobe.com/xap/1.0/rights/In RTF body
    • http://schemas.microsoft.com/office/word/2003/wordml}}\paperw11906\paperh16838\margl1701\margr850\margt1134\margb1134\gutter0\ltrsectIn RTF body

Extracted artifacts 7

Files carved from inside the sample during analysis.

FilenameKindSourceSize
objdata_00_off00000025.bin rtf-objdata-decoded RTF \objdata at offset 0x25 205 bytes
SHA-256: 75a725fc96463ea024899f12597b26031b1a5d84ddd2de407d47914073b3db59
objdata_01_off000001ea.bin rtf-objdata-decoded RTF \objdata at offset 0x1EA 883403 bytes
SHA-256: d0a1edd33e8e7a6deb6d4895ddf8d577282b89c1c0a2d3832eaf162910ea606f
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact entropy is 7.46, consistent with packed or encrypted content.
objdata_02_off001c7de0.bin rtf-objdata-decoded RTF \objdata at offset 0x1C7DE0 1068 bytes
SHA-256: 2b28d78ceb2a564ae30f2b6865926b068f3f920a373c2e3fc4cb865091eddd89
objdata_03_off001c866b.bin rtf-objdata-decoded RTF \objdata at offset 0x1C866B 36440 bytes
SHA-256: 11290e69c3c7b88f22214230479dc467fca6f42052bbffde39374a45d783de7d
objdata_04_off001da34d.bin rtf-objdata-decoded RTF \objdata at offset 0x1DA34D 369 bytes
SHA-256: 3c0b4878e98d51d984a06b9ba36e54869ecd67e41f335730fced4ca28976d877
objdata_05_off001da663.bin rtf-objdata-decoded RTF \objdata at offset 0x1DA663 890 bytes
SHA-256: 21dcdf875b1972c61c0e8c2c2123f9a95c8f29fb4a2cf8bf52511b328881de8e
objdata_06_off001dadbe.bin rtf-objdata-decoded RTF \objdata at offset 0x1DADBE 2633 bytes
SHA-256: 27c6d10cfe7974ebf40c1200cc005f9878cc37b7d49ece9cbc396d700c38918a