Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 26c09e11e1095a19…

MALICIOUS

RTF / .DOC

291.7 KB First seen: 2021-01-02
MD5: f25eb8dcf7ea601039adb40733385578 SHA-1: 64f1d06320641f68c29563b479dec38622201666 SHA-256: 26c09e11e1095a1905a5e68fad4e91bb1594b4d43291ee750f4aa442f427d28b
320 Risk Score

Malware Insights

MITRE ATT&CK
T1559.001 Component Object Model Hijacking T1137.001 DLL Search Order Hijacking

The RTF document contains multiple OLE objects, with high-confidence heuristics indicating automatic linking and update mechanisms that trigger OLE activation. This suggests the document is designed to exploit these OLE features to execute embedded malicious code. No specific family could be identified, and no external IOCs were extracted.

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 9898055bd0 6 samples

Extracted artifacts 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
objdata_00_off000007f8.bin rtf-objdata-decoded RTF \objdata at offset 0x7F8 44551 bytes
SHA-256: 3abd0500d05b8f8f8956c8b3816a4b411a9cb49dbe6888008a59dbb5d1a42c7e
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Static shellcode analysis recovered command string(s): Wscript.Shell"" ) ")
objdata_01_off00004106.bin rtf-objdata-decoded RTF \objdata at offset 0x4106 44525 bytes
SHA-256: 89fa6e00483ff7fbe9ffd427bc50f32fc40ac260acf8731d6f2f4b4b0b6fbcd3
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Static shellcode analysis recovered command string(s): Wscript.Shell"" ) ")
objdata_02_off0001ab6b.bin rtf-objdata-decoded RTF \objdata at offset 0x1AB6B 2632 bytes
SHA-256: 9898055bd0f8f4ea4768ba3581db647387d886eacf12252bf69adb6e4fce9c36
objdata_03_off0001c10e.bin rtf-objdata-decoded RTF \objdata at offset 0x1C10E 12297 bytes
SHA-256: e8d4fe950caed6dcfde26f4b616825bbe11b93458425974b7d075167f675abf7