Malicious PDF — malware analysis report

Static analysis result for SHA-256 54f18e9fd8d8239e…

MALICIOUS

PDF

173.5 KB Created: 2009-07-07 21:23:42 +08:00
MD5: 00ab49a6766f59687bffc04461cb72b3 SHA-1: 38e6fc796e32b0ae96823c241954358c22cdf583 SHA-256: 54f18e9fd8d8239e931cf03c15c466bbec660fa7a155d6cb217885d2ef61b91f
256 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 PowerShell T1204.002 Malicious Link T1566.002 Spearphishing Attachment

This PDF was flagged by ClamAV as Pdf.Dropper.Agent-7212991-0 and also triggered critical heuristics for embedded JavaScript and eval/unescape calls. An extracted JavaScript file, stream_004_off00000674.js, was also identified as suspicious. The presence of these indicators strongly suggests the PDF is designed to exploit vulnerabilities and download further malicious content. The ML classifier also provided a high confidence score for maliciousness.

Machine Learning

  • Nyx PDF Classifier malicious score 0.8043

Heuristics 9

  • ClamAV: Pdf.Dropper.Agent-7212991-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Dropper.Agent-7212991-0
  • ClamAV detection on extracted artifact critical EXTRACTED_FILE_CLAMAV
    ClamAV flagged at least one file extracted from inside this sample. Even when the wrapping document carries no AV detection of its own, a hit on the carved artifact is a strong indicator the sample is a delivery vehicle.
  • eval() call high PDF_EVAL
    eval() found — commonly used for obfuscated exploit execution (matched inside decoded stream)
  • unescape() call high PDF_UNESCAPE
    unescape() found — often used to decode shellcode in PDF JS exploits (matched inside decoded stream)
  • JavaScript action low PDF_JAVASCRIPT
    PDF contains a /JavaScript action. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules. (matched inside decoded stream)
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules. (matched inside decoded stream)
  • Embedded file low PDF_EMBEDDED
    PDF embeds a file attachment — could carry an executable or another weaponised document as a nested payload (matched inside decoded stream)
  • 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.
  • 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://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://ns.adobe.com/xap/1.0/
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/pdf/1.3/

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
stream_004_off00000674.js
2c80bdd3d6b91ebbda4509cf43bc8591224ecc61f53e390b523a7f4ae7dbdfe7
decompressed-pdf-stream PDF FlateDecoded stream at offset 0x674 5027 bytes
Detection
ClamAV: Pdf.Exploit.Agent-35646
Obfuscation or payload: likely
Carved artifact contains 5 eval/decoder/string-building token(s).
objstm_0026_00.bin
9c0baebce7553b4739cd2cb1428834b48d2da40c9481814818257322b116307a
pdf-objstm-decoded PDF /ObjStm 26 0 obj (inflated) 306 bytes