Malicious RTF — malware analysis report

Static analysis result for SHA-256 29e439d60f7fd1fb…

MALICIOUS

RTF

314.2 KB First seen: 2021-05-04
MD5: e5e047cebac68adab0767c248ea09b7f SHA-1: a51bebabd029ce486d64647f75dfbd4951ce7178 SHA-256: 29e439d60f7fd1fb2203ec8cc1a4fdfcdacd78863bccc859ef2774e005f42715
340 Risk Score

Malware Insights

MITRE ATT&CK
T1204.002 Malicious File T1566.001 Spearphishing Attachment

The RTF file contains multiple OLE object heuristics, including automatic linking and update triggers, indicating it's designed to activate embedded content. The document body explicitly instructs the user to 'Enable Editing' and 'download the document', which is a common lure for macro-enabled malware. The presence of embedded OLE objects suggests the potential for executing arbitrary code or downloading further stages.

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_off00000965.bin rtf-objdata-decoded RTF \objdata at offset 0x965 49687 bytes
SHA-256: c9f0c696afa29b4fae7db098082965c0577e44eb113cb07d227609349cf4b3e0
objdata_01_off00007114.bin rtf-objdata-decoded RTF \objdata at offset 0x7114 49660 bytes
SHA-256: fd97cb0f9a2fa4f20d713c2e4a174893fe859dd0e04a8b289f5be946eea99380
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Static shellcode analysis recovered command string(s): WScript.Shell"")")
objdata_02_off00020531.bin rtf-objdata-decoded RTF \objdata at offset 0x20531 2632 bytes
SHA-256: 3cd3b7d42e5855c90d6d11c54ef2670ed8970441480cc23f7d39ef08fa1c935b
objdata_03_off00021ad4.bin rtf-objdata-decoded RTF \objdata at offset 0x21AD4 12297 bytes
SHA-256: e8d4fe950caed6dcfde26f4b616825bbe11b93458425974b7d075167f675abf7