Malicious RTF — malware analysis report

Static analysis result for SHA-256 111e938c7513db09…

MALICIOUS

RTF

28.1 KB
MD5: 2fabe873166b42d734a12c918f792764 SHA-1: c44461e269063c730c77e61ef46bbecfb58e88cf SHA-256: 111e938c7513db09773aee4977645cb85282b0a1ee0a930dfe30078fd235437d
122 Risk Score

Malware Insights

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

The RTF document contains an embedded OLE object that leverages a known vulnerability in the Equation Editor component. The critical heuristic firing for RTF_EQUATION_EDITOR, along with RTF_OBJDATA and RTF_OBJUPDATE, strongly indicates exploitation of this vulnerability. This exploitation is likely used to download and execute a second-stage payload, as suggested by the suspicious extracted artifact.

Heuristics 4

  • Split hex Equation Editor ProgID + OLE object critical 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
  • Suspicious extracted artifact info 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.

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
objdata_00_off00001eca.bin
7d4da224054a2549d532108895c3357b483d5015dc4f0b09a250a978d828e5e8
rtf-objdata-decoded RTF \objdata at offset 0x1ECA 6246 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact entropy is 7.58, consistent with packed or encrypted content.