Malicious RTF — malware analysis report

Static analysis result for SHA-256 2065248cbda5fede…

MALICIOUS

RTF

535.8 KB First seen: 2019-05-10
MD5: 344f2b5f0bb89f29b4ef9852f1b87265 SHA-1: fc7436a84b82a16f423799ee5d1a80a9c0cc417f SHA-256: 2065248cbda5fedee2bf6954f4c58be803cfffca3763ceb0b46bb4e57099dc8f
184 Risk Score

Malware Insights

MITRE ATT&CK
T1203 Exploitation for Client Execution

The RTF file contains multiple indicators of malicious OLE object embedding and specifically fires critical heuristics for CVE-2017-8570, which is known to drop SCT scripts. The embedded OLE object data, particularly objdata_01_off000001ee.bin, likely contains the malicious script payload. The exploit facilitates client execution by leveraging a known vulnerability.

Heuristics 7

  • 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.
  • OLE object data medium RTF_OBJDATA
    RTF contains 9 \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://nsis.sf.net/NSIS_Error In RTF body

Extracted artifacts 8

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: 980870ba17beb12f03c3941a0cfa655d820816cec9104090156a6ea6ece5ce8a
objdata_01_off000001ee.bin rtf-objdata-decoded RTF \objdata at offset 0x1EE 258177 bytes
SHA-256: 33dfa2fb5354e8f111c0b171ba81646a4ab8f3d247f4e20dddb2f50688cfa1a0
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact entropy is 7.93, consistent with packed or encrypted content.
objdata_02_off00081df9.bin rtf-objdata-decoded RTF \objdata at offset 0x81DF9 990 bytes
SHA-256: 819742f5c84cbe7b646f281a2d66b550ab90b6860c2f5bde5cdca478f30b59a9
objdata_03_off000825ee.bin rtf-objdata-decoded RTF \objdata at offset 0x825EE 612 bytes
SHA-256: c62851521e10316dfd43f2b6ee67cc27e2a24456bb346c8fa9dc4a6d6e21d526
objdata_04_off00082aee.bin rtf-objdata-decoded RTF \objdata at offset 0x82AEE 380 bytes
SHA-256: 17e63036be0dbac77e35be89dbbfbf4e8c5055136fd574d2fd6018a721b22af7
objdata_05_off00082e22.bin rtf-objdata-decoded RTF \objdata at offset 0x82E22 882 bytes
SHA-256: e0dd860bb62dee2108b913a024deb7f63abfad8765c6af0041159382d16d8717
objdata_06_off00083584.bin rtf-objdata-decoded RTF \objdata at offset 0x83584 2633 bytes
SHA-256: fe11c27d916ab897eb94064e9631d8a29c847a6db39259bef31578da8d19fdf5
objdata_07_off00084a9c.bin rtf-objdata-decoded RTF \objdata at offset 0x84A9C 2601 bytes
SHA-256: 67ff079a9b0f053ca2843811d9da7a8fdedc7d9d377ef39d09dde148b9657c7f