Malicious RTF — malware analysis report

Static analysis result for SHA-256 893760b12d76ee78…

MALICIOUS

RTF

261.2 KB Created: 2018-07-03 09:28:00 First seen: 2019-03-18
MD5: 1b3fc93c16e9de9765e46836f00a00d6 SHA-1: 69563310a6b2c8e2a13c323589c1b9e6072af1eb SHA-256: 893760b12d76ee78a33bc8e4f6530c19f6b2de32822a02b683c768ee63d2a641
262 Risk Score

Malware Insights

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

The RTF file contains critical heuristic firings for CVE-2017-11882 and CVE-2017-8759, indicating exploitation of known vulnerabilities in Microsoft Equation Editor and MSXML SAX for OLE activation. These exploits are designed to execute embedded objects, which in this case is likely a dropper for a second-stage payload. The embedded URL 'http://litoband.br-rgt.net/secured/jag' is a probable C2 server for downloading this payload.

Heuristics 7

  • CVE-2017-11882 — Equation Editor FONT record overflow critical CVE likely CVE_2017_11882
    Equation Editor MTEF contains an overlong FONT typeface field, the vulnerable copy primitive for CVE-2017-11882. This is stronger evidence than the Equation Editor CLSID alone because it identifies the malformed record that drives code execution in EQNEDT32.EXE.
  • 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: Rtf.Dropper.Agent-6880926-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Rtf.Dropper.Agent-6880926-0
  • \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 1 \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://litoband.br-rgt.net/secured/jag In RTF body
    • http://schemas.microsoft.com/office/word/2003/wordmlIn RTF body

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
objdata_00_off0000bf6b.bin rtf-objdata-decoded RTF \objdata at offset 0xBF6B 15672 bytes
SHA-256: 58803a6a26c7d2ab4825577023aa253e509c632fa1f2fe9b05275d3ab898dce9

Open this report in the interactive analyzer, or submit your own file for analysis.