Malicious RTF — malware analysis report

Static analysis result for SHA-256 b906da37906d2d57…

MALICIOUS

RTF

8.9 KB First seen: 2019-06-27
MD5: 6970247f3e372be1cdc92e08acbf97cb SHA-1: 85db185c69e185900398ee5a178f7d0a91f2d010 SHA-256: b906da37906d2d57aee7ef84e0e8921f46707d378e64f63f942792d0c09438e8
122 Risk Score

Malware Insights

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

The RTF file contains an embedded OLE object with a split Equation Editor ProgID, indicating an attempt to exploit a known vulnerability in the Equation Editor component. The \objupdate directive forces OLE object activation, which is a common technique for executing embedded exploits. This likely leads to arbitrary code execution on the victim's machine, commonly delivered via spearphishing attachments.

Heuristics 4

  • Split hex Equation Editor ProgID + OLE object critical CVE likely RTF_EQUATION_EDITOR
    RTF embeds the Equation.3 ProgID as hex bytes near OLE object activation and splits the byte stream with whitespace or an ignorable RTF group. This is an Equation Editor OLE activation surface commonly used by CVE-2017-11882 / CVE-2018-0802 exploit documents.
  • \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 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 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
objdata_00_off00001661.bin rtf-objdata-decoded RTF \objdata at offset 0x1661 1347 bytes
SHA-256: 830d31df7bfab0cc63ce0b512508b01dc4a41cd93a313ab750611d33764448d5