Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 635624028186b883…

MALICIOUS

RTF / .DOC

348.3 KB
MD5: 7f3f0494cb5fd0e07472182ebf4c1392 SHA-1: 588d8f3cdcd9ac15a7afe683732aa71ee25eb8ea SHA-256: 635624028186b883be0794d4f5e929de60cb87fdf9ec488a0718d43fbc2ec6bb
122 Risk Score

Malware Insights

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

The RTF document contains OLE object data and specifically triggers the Equation Editor vulnerability, indicating exploitation for client execution. The embedded OLE object, objdata_00_off00001161.bin, is likely the malicious payload or a component thereof. The presence of ".objupdate" suggests an attempt to automatically activate the embedded object, facilitating the exploit. Given these factors, the most probable attack pattern is a spearphishing attachment leading to exploitation.

Heuristics 4

  • Equation Editor CLSID critical RTF_EQUATION_EDITOR
    Equation Editor OLE CLSID found inside an OLE object — exploited by CVE-2017-11882 / CVE-2018-0802 / CVE-2018-0798
  • \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_off00001161.bin
905f2190c0e66fce447fe53e76e990d945e6f011003263b8e12be2f191b46a49
rtf-objdata-decoded RTF \objdata at offset 0x1161 64063 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact entropy is 7.93, consistent with packed or encrypted content.