Malicious PDF — malware analysis report

Static analysis result for SHA-256 54760e5d4ef927c7…

MALICIOUS

PDF

238.1 KB Created: 2017-11-24 14:20:55 Authoring application: Joomla! 1.5 - Open Source Content Management (via TCPDF 2.5.000_PHP4 (http://www.tcpdf.org))
MD5: 6604895a89415409ebeb72e9b3043129 SHA-1: 3e7c122c7fc54d44b3cd7611264f67237bda268c SHA-256: 54760e5d4ef927c7bdad3ec82ad91184d8782c4d54160b178c56333df79ebfaf
60 Risk Score

Malware Insights

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

The PDF was flagged by a machine learning classifier with high confidence and also triggered heuristics related to embedded script payloads and string obfuscation. The presence of an embedded script payload suggests an attempt to execute malicious code, likely for downloading and executing a second-stage payload. The ML classifier's high score indicates a strong likelihood of malicious intent.

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
b454bba17e25e6b570717c2eddc12919b5ce271cfcf3627dd494e794ec99d171
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).