Malicious RTF — malware analysis report

Static analysis result for SHA-256 57bb59a2c491b89b…

MALICIOUS

RTF

662.3 KB First seen: 2026-05-24
MD5: 47a5e618c809f1f37bccced9d3536deb SHA-1: da3a6f5851537edffcc29e9bf4282d552090ce6e SHA-256: 57bb59a2c491b89b3321428121ba1b5e88daca5a8e379fde41afc73e9679d752
340 Risk Score

Malware Insights

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

The RTF document contains multiple indicators of exploitation, specifically related to CVE-2017-8570 and CVE-2017-0199/CVE-2017-8759, which are used to automatically download and execute a second-stage payload. The document body explicitly instructs the user to 'click Enable Editing', a common lure to bypass security measures and facilitate the execution of embedded malicious content. The embedded OLE objects and objdata sections are the likely carriers of the exploit and payload.

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_off00000965.bin rtf-objdata-decoded RTF \objdata at offset 0x965 221069 bytes
SHA-256: 3774e36c866cbfeef8538f5248205f2a88e939c4e7d51e4f19360d050cf7abcf
objdata_01_off00007114.bin rtf-objdata-decoded RTF \objdata at offset 0x7114 221042 bytes
SHA-256: 72c4a0d6c14effd2bd17f743c01cad02c8d5db027de3dca1f3f37e17d7f35776
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Static shellcode analysis recovered command string(s): WScript.Shell"")")
objdata_02_off000775ab.bin rtf-objdata-decoded RTF \objdata at offset 0x775AB 2632 bytes
SHA-256: 51ef705eef602ac6eb91c2063c8f50d4e54b5e051b60429031d41133bc7df645
objdata_03_off00078b4e.bin rtf-objdata-decoded RTF \objdata at offset 0x78B4E 12297 bytes
SHA-256: e8d4fe950caed6dcfde26f4b616825bbe11b93458425974b7d075167f675abf7