Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 ffdfa8e7d36238ac…

MALICIOUS

RTF / .DOC

295.5 KB First seen: 2021-05-04
MD5: 191f38f0ef0adca84572330b29a32034 SHA-1: 358ebb28a5a5adf4bfccc1199901a91156063101 SHA-256: ffdfa8e7d36238ac625b595ff40cc2faae7b76a5b1a85579943c4b42cd4738fe
340 Risk Score

Malware Insights

MITRE ATT&CK
T1204 Malicious Link T1204.002 Malicious Link: Malicious File T1566 Phishing T1566.001 Phishing: Spearphishing Attachment T1059 Command and Scripting Interpreter T1059.005 Command and Scripting Interpreter: Visual Basic

The file is an RTF document that uses OLE object data and auto-linking to exploit vulnerabilities. The document body contains a lure instructing the user to 'Enable Editing' to bypass Office macro security settings, indicating it functions as a malware dropper. No specific scripts were extracted, but the OLE object structure suggests it's designed to execute embedded malicious content upon activation.

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 3cd3b7d42e 51 samples

Extracted artifacts 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
objdata_00_off0000096e.bin rtf-objdata-decoded RTF \objdata at offset 0x96E 40504 bytes
SHA-256: b240b561807f0e6cde435e845969882278be07d543032e4d59ad05576d03f10e
objdata_01_off0000711d.bin rtf-objdata-decoded RTF \objdata at offset 0x711D 40477 bytes
SHA-256: 56980e073a6b930841a1286ff54debfc5df19a61f23c61829915c6e086b71194
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Static shellcode analysis recovered command string(s): WScript.Shell"")")
objdata_02_off0001ba9e.bin rtf-objdata-decoded RTF \objdata at offset 0x1BA9E 2632 bytes
SHA-256: 3cd3b7d42e5855c90d6d11c54ef2670ed8970441480cc23f7d39ef08fa1c935b
objdata_03_off0001d041.bin rtf-objdata-decoded RTF \objdata at offset 0x1D041 12297 bytes
SHA-256: e8d4fe950caed6dcfde26f4b616825bbe11b93458425974b7d075167f675abf7