Malicious PDF — malware analysis report

Static analysis result for SHA-256 fa4f8d8ac27481cd…

MALICIOUS

PDF

59.1 KB Created: 2009-08-30 00:20:17 UTC Authoring application: AdobePS5.dll Version 5.2.2 (via Mac OS X 10.5.8 Quartz PDFContext)
MD5: c25e02b7677d57d6a44104cf3fdddc80 SHA-1: 67828fcf209fa9f307814d187fa24e169d667141 SHA-256: fa4f8d8ac27481cdfc3725f4cd70e60dfb4c672ab439b45d2eaa0f9566338b4b
514 Risk Score

Malware Insights

MITRE ATT&CK
T1204.002 Malicious File T1059.001 PowerShell T1566.001 Spearphishing Attachment T1204.001 Malicious Link T1059.003 Windows Command Shell

This PDF file contains a critical PDF_LAUNCH heuristic firing, indicating it attempts to execute a command via cmd.exe. The embedded JavaScript and the PDF_LAUNCH_PLUS_DROPPER_JS heuristic confirm that the document is designed to drop and execute an embedded file, which was identified as a Windows executable by ClamAV (Win.Trojan.MSShellcode-7). The embedded file is masquerading as 'form.pdf' but is actually a Windows executable.

Machine Learning

  • Nyx PDF Classifier malicious score 1.0000

Heuristics 11

  • Adobe Reader Launch action command execution critical CVE exact CVE_2010_1240
    PDF uses the Adobe Reader/Acrobat Launch action pattern associated with CVE-2010-1240: cmd.exe is invoked with attacker-controlled parameters, paired with an embedded/exported payload.
  • Launch action critical PDF_LAUNCH
    PDF contains a /Launch action whose target is an executable, URL, or UNC path — can start an external application
  • Embedded Windows executable payload in PDF stream critical PDF_EMBEDDED_PE_PAYLOAD
    PDF stream bytes contain an embedded Windows executable with a verified PE header. Exploit chains often hide droppers inside ordinary streams rather than standard /EmbeddedFile attachments.
  • /Launch action target: cmd.exe critical PDF_LAUNCH_COMMAND
    PDF /Launch action specifies an executable target with parameters '/Q /C %HOMEDRIVE%&cd %HOMEPATH%&(if exist "Desktop\\form.pdf" (cd "Desktop"' — references a known-dangerous executable (cmd, PowerShell, etc.).
  • Embedded attachment masquerades: declared document, content is windows-executable critical PDF_EMBEDDED_FILESPEC_CONTENT_MISMATCH
    An /EmbeddedFile attachment's declared filename extension or /Subtype MIME type contradicts the magic bytes of its decompressed content. The attachment is declared as a benign document or image but the bytes are an executable or executable-bearing archive. This is a deliberate deception used to hide droppers in PDF attachments and is a generic indicator of embed-and-drop weaponisation, independent of any specific CVE.
  • ClamAV: Pdf.Dropper.Agent-7326839-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Dropper.Agent-7326839-0
  • 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.
  • /Launch action paired with attachment-dropping JS API high PDF_LAUNCH_PLUS_DROPPER_JS
    PDF combines a /Launch action with a JavaScript API call that writes or opens an attached/external resource — the canonical shape of the CVE-2010-1240 /Launch + exportDataObject family. Benign PDFs do not pair these surfaces; the combination indicates a drop-and-execute chain regardless of the specific JS API knobs or /Launch target.
  • 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.
  • 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.
  • Embedded file low PDF_EMBEDDED
    PDF embeds a file attachment — could carry an executable or another weaponised document as a nested payload

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
form.pdf
d3ed08b50b2cd7aebc29b7379827abbeb627bca256fcdece04ee9b75c682f0d0
pdf-embedded-file PDF EmbeddedFile object 21 at offset 0x3B9E 73802 bytes
Detection
ClamAV: Win.Trojan.MSShellcode-7
Obfuscation or payload: unlikely
javascript_obj0022_000.js
eff4a0943aaff2d99cb5c8666337775c91d4d5f687782df94d2c5fc77becde7f
pdf-javascript-stream PDF /JS object 22 at offset 0xE84C 53 bytes
icc_00_off000002d6.icc
2b3aa1645779a9e634744faf9b01e9102b0c9b88fd6deced7934df86b949af7e
pdf-icc-profile PDF ICC profile at offset 0x2D6 3144 bytes