Malicious PDF — malware analysis report

Static analysis result for SHA-256 2e950bc12ffa9d15…

MALICIOUS

PDF

238.1 KB Created: 2017-11-18 15:37:42 Authoring application: Joomla! 1.5 - Open Source Content Management (via TCPDF 2.5.000_PHP4 (http://www.tcpdf.org))
MD5: afdc586112713c87329e955207c7d262 SHA-1: 2af4ceca0c858fc04730aa7d8070ba67ef8ebceb SHA-256: 2e950bc12ffa9d15087c797b9c0ac84513ff8d7de8ad40e6f9c4c2c2c9e511fa
60 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 PowerShell T1204.002 Malicious File

The PDF file contains an embedded script payload, as indicated by the 'PDF_EMBEDDED_SCRIPT_PAYLOAD' heuristic and the 'ML_NYX_PDF_MALICIOUS' classifier. The script is obfuscated and likely intended to download and execute a second-stage payload. The 'PDF_FROMCHARCODE' heuristic further suggests string manipulation commonly used in obfuscated scripts.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9504

Heuristics 3

  • Embedded script payload in PDF stream medium PDF_EMBEDDED_SCRIPT_PAYLOAD
    PDF stream bytes contain an HTML/XFA <script> tag without accompanying Windows shell-execution primitives — common in accessible XFA forms but worth surfacing for analyst review.
  • String.fromCharCode low PDF_FROMCHARCODE
    String.fromCharCode found — used to construct payload strings dynamically. Common in benign JavaScript libraries for codepoint manipulation, so this alone is informational; weaponised use is also caught by the dedicated fromCharCode-stage and exploit-shape rules.
  • 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 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
stream_002_off0000b783.bin
a5337ef1f5a0dfe4dc8fa6b4f3ef847a53624800b5928a0eeef5b888ceecaabc
decompressed-pdf-stream PDF FlateDecoded stream at offset 0xB783 264072 bytes
embedded_pdf_script_0003a937.bin
7ecb1f6f5a1fa8e9a0f7b095f32cfb16468c6c8d86ac1bc31404d319b8c6e9a7
pdf-embedded-script PDF decompressed stream script payload at offset 0x3A937 243782 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 1 eval/decoder/string-building token(s).