Malicious RTF — malware analysis report

Static analysis result for SHA-256 76de0fbc2eba0e6f…

MALICIOUS

RTF

662.9 KB First seen: 2026-06-04
MD5: c801b26fae70ab85b1d374f04e491135 SHA-1: bedcd40f219f8d57d45d0b066502ed55a6614047 SHA-256: 76de0fbc2eba0e6f5e2ac97f0626106dc68a8162eeb7a75c7f178714762be0e7
340 Risk Score

Malware Insights

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

The RTF file contains multiple indicators of OLE object manipulation, specifically leveraging CVE-2017-8570 and CVE-2017-0199/CVE-2017-8759. These vulnerabilities allow the embedded OLE object to automatically execute a remote loader, which likely downloads and executes a secondary payload. The document body contains a lure to 'Enable Editing', further supporting the malicious intent.

Heuristics 9

  • 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
  • Macro/content-enable lure medium SE_ENABLE_LURE
    Document instructs the user to enable macros or editing — a common technique used by malware droppers to bypass Office macro security settings
🗂 Part of campaign: shared payload 51ef705eef 49 samples

Extracted artifacts 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
objdata_00_off00000bac.bin rtf-objdata-decoded RTF \objdata at offset 0xBAC 221101 bytes
SHA-256: 579dbb489d0ecf041580f0ceaf4d922a8ec4c1eaec4479a1e2f4bba2f9cf10ed
objdata_01_off0000735b.bin rtf-objdata-decoded RTF \objdata at offset 0x735B 221074 bytes
SHA-256: fe145acd831ec24accb4c9e4c973d259c807728243f417ff211033f1d4109991
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Static shellcode analysis recovered command string(s): WScript.Shell"")")
objdata_02_off00077836.bin rtf-objdata-decoded RTF \objdata at offset 0x77836 2632 bytes
SHA-256: 51ef705eef602ac6eb91c2063c8f50d4e54b5e051b60429031d41133bc7df645
objdata_03_off00078dd9.bin rtf-objdata-decoded RTF \objdata at offset 0x78DD9 12297 bytes
SHA-256: e8d4fe950caed6dcfde26f4b616825bbe11b93458425974b7d075167f675abf7