Malicious PDF — malware analysis report

Static analysis result for SHA-256 53a7e6e4e823f92c…

MALICIOUS

PDF

244.6 KB
MD5: eeffebb950d980b93034026fe0d34ca6 SHA-1: c987e327eb5d1838f00bb4ad775b0fc780f61855 SHA-256: 53a7e6e4e823f92c53abe68e3e5e2b9259665ac84cc2b7b72bb770641b145a79
330 Risk Score

Malware Insights

MITRE ATT&CK
T1059.003 Windows Command Shell T1204.002 Malicious File

The PDF file contains a launch action that executes cmd.exe, indicating an attempt to run a command-line payload. This payload is likely responsible for downloading and executing a secondary stage, as suggested by the embedded script and ClamAV detections of dropper-type malware. The ML classifier also strongly flagged this PDF as malicious.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9999

Heuristics 6

  • 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.).
  • ClamAV: Win.Trojan.Dropper-132 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Win.Trojan.Dropper-132
  • 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.
  • 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.
  • Suspicious extracted artifact medium 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
embedded_pdf_script_0003cc93.bin
1124f120bd8bafb8059b73836ec0399f4abe013887522f00049e7f6a94bd7155
pdf-embedded-script PDF raw stream script payload at offset 0x3CC93 248958 bytes
Detection
ClamAV: Win.Trojan.Dropper-133
Obfuscation or payload: likely
Carved artifact contains 2 shell/COM execution token(s).