Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 479359b567cee405…

MALICIOUS

RTF / .DOC

346.9 KB First seen: 2021-06-28
MD5: 4cbdbe42f996bfc6ba2c562c363157e0 SHA-1: 92e4078d7cc6a5e8d7095bd24395734ff6120f00 SHA-256: 479359b567cee405775f024ce15266469841505674c198ec25468d89151a5e1f
320 Risk Score

Malware Insights

MITRE ATT&CK
T1559.001 Component Object Model T1204.002 Malicious File

The RTF document contains multiple OLE objects, with several heuristics indicating automatic linking and update mechanisms. These features suggest the file is designed to exploit OLE vulnerabilities to execute embedded malicious content when opened. No document body or script content was available for further analysis.

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.
  • CVE-2017-0199 / CVE-2017-8759 (OLE2Link auto-activated remote loader) critical CVE related RTF_OLE2LINK_REMOTE_MONIKER_LOADER
    RTF embeds an OLE2Link object that is force-activated with \objupdate (no user interaction on open) and fetches a remote second stage — through an INCLUDETEXT/INCLUDEPICTURE field or the OLE object's own moniker. This is the OLE2Link auto-update attack path shared by CVE-2017-0199 (server returns an HTA/scriptlet) and CVE-2017-8759 (server returns a SOAP WSDL the .NET parser compiles). Office processes the fetched response through the same code path; the specific CVE depends on the now-unreachable server content type.
  • 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.
  • 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.
  • Suspicious extracted artifact high 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.
  • OLE object data medium RTF_OBJDATA
    RTF contains 4 \objdata section(s) — embedded OLE objects
  • Embedded OLE object medium RTF_OBJEMB
    RTF contains \objemb — embedded OLE object
🗂 Part of campaign: shared payload 3cd3b7d42e 51 samples

Extracted artifacts 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
objdata_00_off000007da.bin rtf-objdata-decoded RTF \objdata at offset 0x7DA 65990 bytes
SHA-256: 17d101bf271663e80df0c4f1bbf6a7e35eb82f9d1589237fc108091e053e5cca
objdata_01_off00006f89.bin rtf-objdata-decoded RTF \objdata at offset 0x6F89 65963 bytes
SHA-256: d2a4d54c85100a373cb80e19d1b88f4c190d0f27e9b56436f040ac0329391b04
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Static shellcode analysis recovered command string(s): WScript.Shell"")")
objdata_02_off0002881c.bin rtf-objdata-decoded RTF \objdata at offset 0x2881C 2632 bytes
SHA-256: 32e8e449cdc043249ce37c79c9eaf2af80a02cb8175718a8a0ce726d961b7d16
objdata_03_off00029dbf.bin rtf-objdata-decoded RTF \objdata at offset 0x29DBF 12297 bytes
SHA-256: e8d4fe950caed6dcfde26f4b616825bbe11b93458425974b7d075167f675abf7