Malicious RTF — malware analysis report

Static analysis result for SHA-256 0a15805f80a997d7…

MALICIOUS

RTF

876.3 KB Created: 2018-04-27 02:02:00 First seen: 2018-06-21
MD5: 22a83ea7860d797c5b488f7d4fd13dfc SHA-1: 634634d75af161df775445afcd893a2655cbe85e SHA-256: 0a15805f80a997d79804c22d4fc975f4cdbb270a8285535d83dcf60d99528c47
262 Risk Score

Malware Insights

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

The RTF file contains multiple embedded OLE objects and triggers an ".objupdate" command, which is indicative of exploiting vulnerabilities like CVE-2017-8759 for client execution. ClamAV detections further confirm its malicious nature, flagging it as Doc.Macro.Obfuscation. The primary attack vector is likely spearphishing attachment, with the embedded OLE object serving as the mechanism to download and execute a secondary payload.

Heuristics 6

  • CVE-2017-8759 — MSXML SAX OLE activation critical CVE likely CVE_2017_8759
    RTF contains a hex-encoded OLE1 object for Msxml2.SAXXMLReader.6.0 followed by an embedded OLE compound document, and the document requests OLE activation. This matches the RTF staging shape used for CVE-2017-8759 SOAP/WSDL parser code injection.
  • ClamAV: Doc.Dropper.Agent-6412232-1 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Doc.Dropper.Agent-6412232-1
  • \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.
  • OLE object data medium RTF_OBJDATA
    RTF contains 12 \objdata section(s) — embedded OLE objects
  • Embedded OLE object medium RTF_OBJEMB
    RTF contains \objemb — embedded OLE object
  • Embedded URL info EMBEDDED_URL
    One or more URLs were extracted from the document. The URL itself is not a detection — see the per-URL labels for which channel (macro, JS, link annotation, document body, ...) reached each URL.
    URL http://schemas.microsoft.com/office/word/2003/wordml In RTF body

Extracted artifacts 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
objdata_00_off00002c14.bin rtf-objdata-decoded RTF \objdata at offset 0x2C14 24123 bytes
SHA-256: b036cd08d65d0d88254d6c452e5be00a8df37a12c7f1bb6e692ffd2b12f5a533
Detection
ClamAV: Doc.Dropper.Agent-6412232-1
Obfuscation or payload: unlikely
objdata_01_off0001429a.bin rtf-objdata-decoded RTF \objdata at offset 0x1429A 24123 bytes
SHA-256: 2016b8d2ac20c5cc27088a37193662e8d7ba1263c10d1fb9fb660ffad44a9697
Detection
ClamAV: Doc.Dropper.Agent-6412232-1
Obfuscation or payload: unlikely
objdata_03_off00036fa6.bin rtf-objdata-decoded RTF \objdata at offset 0x36FA6 24123 bytes
SHA-256: 9af20ae319b1979817c719919ceb495b30b6f27ea18d901b02301f651578d7fc
Detection
ClamAV: Doc.Dropper.Agent-6412232-1
Obfuscation or payload: unlikely
objdata_10_off000b0d9a.bin rtf-objdata-decoded RTF \objdata at offset 0xB0D9A 24123 bytes
SHA-256: 10521583df3be968f9e72bb9075e7314ae01f909c86d7a1cb7d93cec8062a559
Detection
ClamAV: Doc.Dropper.Agent-6412232-1
Obfuscation or payload: unlikely