Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 3fda6eb4d9082882…

MALICIOUS

RTF / .DOC

318.6 KB
MD5: 0ea6e37e930278b71774ae91d68bb879 SHA-1: 5e3721c21b04c30c0f2d3b7e83b7bb506fd55cb8 SHA-256: 3fda6eb4d90828826854806f1956d0d4a20bf5f95eb917370ff05ba5ba1dde66
182 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Phishing: Spearphishing Attachment T1204.002 Malicious File: Malicious Link

The file is identified as malicious due to critical heuristic firings indicating the exploitation of CVE-2017-11882 via the Equation Editor vulnerability. The presence of OLE object data and an explicit ".objupdate" command further supports this. The attack pattern involves leveraging this known vulnerability to execute arbitrary code, likely leading to the download and execution of a second-stage payload.

Heuristics 5

  • 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
  • ClamAV: Rtf.Exploit.CVE_2017_11882-6584355-1 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Rtf.Exploit.CVE_2017_11882-6584355-1
  • \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 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_off0000142e.bin
fcd7e6251a6715fb3e1337ad34e9253ae2c29ad0f16be7d2b65436c759bbc9e4
rtf-objdata-decoded RTF \objdata at offset 0x142E 160348 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact entropy is 7.98, consistent with packed or encrypted content.