Malicious RTF — malware analysis report

Static analysis result for SHA-256 8ea8fa1a31819761…

MALICIOUS

RTF

661.9 KB First seen: 2026-06-04
MD5: 85ac7e1bb3a626ed3da28b9a37ecb19d SHA-1: 0ea433ba453e53162bb903cb3c69d075478903f3 SHA-256: 8ea8fa1a31819761e6997035f62e95ab894053fb630f9f2adeb2a44686166937
320 Risk Score

Malware Insights

MITRE ATT&CK
T1203 Exploitation for Client Execution

The RTF document contains OLE objects and utilizes Composite Monikers, indicating exploitation of CVE-2017-8570 and CVE-2017-0199. These vulnerabilities allow the document to automatically load and execute a remote OLE object, which likely serves as a loader for a second-stage payload. The extracted artifact objdata_01_off00006f89.bin is a strong indicator of this malicious activity.

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 51ef705eef 49 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 221081 bytes
SHA-256: 7da7fe93a59d208477a5975b04662f459030b02761ccd15069f11c0e482e54fe
objdata_01_off00006f89.bin rtf-objdata-decoded RTF \objdata at offset 0x6F89 221054 bytes
SHA-256: e918886f3a8349162fa2406f3c1678afd5efa742ca65ea47a507aa5d667c2dde
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Static shellcode analysis recovered command string(s): WScript.Shell"")")
objdata_02_off0007743a.bin rtf-objdata-decoded RTF \objdata at offset 0x7743A 2632 bytes
SHA-256: 51ef705eef602ac6eb91c2063c8f50d4e54b5e051b60429031d41133bc7df645
objdata_03_off000789dd.bin rtf-objdata-decoded RTF \objdata at offset 0x789DD 12297 bytes
SHA-256: e8d4fe950caed6dcfde26f4b616825bbe11b93458425974b7d075167f675abf7