Malicious RTF — malware analysis report

Static analysis result for SHA-256 d5c5bdd98f65cb56…

MALICIOUS

RTF

937.8 KB First seen: 2019-04-18
MD5: a262a1535fd57185af3bd69e22596669 SHA-1: b502ef2b40c99d9545356ffdb2db2e11412e4e35 SHA-256: d5c5bdd98f65cb5634f5e781a5e2f37cdcac764bd4a0f7c3dc04318d8df7b4e5
184 Risk Score

Malware Insights

MITRE ATT&CK
T1203 Exploitation for Client Execution

The RTF file contains OLE object data and triggers heuristics related to CVE-2017-8570, indicating it exploits a vulnerability to drop a script. The embedded OLE object data, specifically objdata_01_off000001ee.bin, is the primary artifact associated with this exploit. The exploit likely leads to the execution of a second-stage payload, potentially JavaScript, given the nature of the CVE.

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://schemas.openxmlformats.org/drawingml/2006/main 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 445131 bytes
SHA-256: 7285b934d298624f56deefff0de29b159b44752ac56e39a45029c70c5d7d9470
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact entropy is 7.85, consistent with packed or encrypted content.
objdata_02_off000d9d09.bin rtf-objdata-decoded RTF \objdata at offset 0xD9D09 990 bytes
SHA-256: 819742f5c84cbe7b646f281a2d66b550ab90b6860c2f5bde5cdca478f30b59a9
objdata_03_off000da4fe.bin rtf-objdata-decoded RTF \objdata at offset 0xDA4FE 26316 bytes
SHA-256: 89d1c0807f4d4dd2dbc3c5357fc9e55a3129223e5915f30eec025828c74b2682
objdata_04_off000e72ce.bin rtf-objdata-decoded RTF \objdata at offset 0xE72CE 380 bytes
SHA-256: 17e63036be0dbac77e35be89dbbfbf4e8c5055136fd574d2fd6018a721b22af7
objdata_05_off000e7602.bin rtf-objdata-decoded RTF \objdata at offset 0xE7602 882 bytes
SHA-256: e0dd860bb62dee2108b913a024deb7f63abfad8765c6af0041159382d16d8717
objdata_06_off000e7d64.bin rtf-objdata-decoded RTF \objdata at offset 0xE7D64 2633 bytes
SHA-256: fe11c27d916ab897eb94064e9631d8a29c847a6db39259bef31578da8d19fdf5
objdata_07_off000e927c.bin rtf-objdata-decoded RTF \objdata at offset 0xE927C 2601 bytes
SHA-256: 67ff079a9b0f053ca2843811d9da7a8fdedc7d9d377ef39d09dde148b9657c7f