Malicious PDF — malware analysis report

Static analysis result for SHA-256 685d2512efad4af6…

MALICIOUS

PDF

159.6 KB
MD5: 9d712fdc8c1a3068b188a2c7aab711f9 SHA-1: dded0b517d40d6b16ee598a971cd2dda31fdd926 SHA-256: 685d2512efad4af64dcf042baa3227dc8bc07c8221b273a8fdf6e8145ac449dd
230 Risk Score

Malware Insights

MITRE ATT&CK
T1059.007 JavaScript T1203 Exploitation for Client Execution T1566.001 Spearphishing Attachment

The PDF file contains a critical PDF_LAUNCH heuristic firing, indicating an attempt to execute a command. The embedded script uses JavaScript to construct and execute a VBScript file named 'launcher.vbs' which is likely responsible for downloading and executing a second-stage payload. The script also references 'exec.pdf' and 'script.vbs', suggesting a multi-stage infection process.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9999

Heuristics 4

  • Launch action critical PDF_LAUNCH
    PDF contains a /Launch action whose target is an executable, URL, or UNC path — can start an external application
  • /Launch action target: cmd.exe critical PDF_LAUNCH_COMMAND
    PDF /Launch action specifies an executable target with parameters '/C echo Set fso=CreateObject\("Scripting.FileSystemObject"\' — references a known-dangerous executable (cmd, PowerShell, etc.).
  • OpenAction trigger high PDF_OPENACTION
    PDF has an /OpenAction that launches, submits, or opens an external target
  • Embedded script payload in PDF stream high PDF_EMBEDDED_SCRIPT_PAYLOAD
    PDF stream bytes contain script execution markers such as ActiveXObject/CreateObject, WScript.Shell, PowerShell, or shell-exec primitives. This is stronger than ordinary PDF JavaScript because it indicates a staged external script payload hidden in stream bytes.

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
embedded_pdf_script_00000068.bin
b289cef1c6d42db57796e339d06e228f2bab7a9d886548cdd581dd767028015d
pdf-embedded-script PDF decompressed stream script payload at offset 0x68 552 bytes