Malicious PDF — malware analysis report

Static analysis result for SHA-256 a5583e6b06a4bb62…

MALICIOUS

PDF

3.3 KB Created: 2008-31-20 53:85:00 Authoring application: Scribus 1.3.3.12 (via Scribus PDF Library 1.3.3.12)
MD5: 8847617459ec6950f427357844ec2038 SHA-1: a0798fd26d91936ca71ee096e079653dec160673 SHA-256: a5583e6b06a4bb62ccbc1460d5543bec9ec47ec73f7e6e6e66ea082d53c2c943
186 Risk Score

Malware Insights

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

The PDF file contains embedded JavaScript, indicated by multiple heuristic firings including PDF_JAVASCRIPT, PDF_JS, and PDF_EVAL. The presence of 'eval()' and 'String.fromCharCode' suggests obfuscated code designed to execute malicious actions. ClamAV detection as 'Pdf.Exploit.Agent-35835' further confirms its malicious nature. The deobfuscated JavaScript likely downloads and executes a secondary payload, a common technique for initial access.

Heuristics 7

  • ClamAV: Pdf.Exploit.Agent-35835 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Exploit.Agent-35835
  • 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.
  • eval() call high PDF_EVAL
    eval() found — commonly used for obfuscated exploit execution (matched inside decoded stream)
  • 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.
  • 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. (matched inside decoded stream)
  • 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
javascript_obj0013_000.js
fddefa6163200f36b0e7073ed41103e1ff534fe5a77931f1c551a146ffbc71b8
pdf-javascript-stream PDF /JS object 13 at offset 0x39C 5885 bytes
Detection
ClamAV: Pdf.Exploit.Agent-35835
Obfuscation or payload: likely
Carved artifact contains 2 eval/decoder/string-building token(s). Carved artifact contains 1 long base64-like blob(s).
deobfuscated.js
977deef813dd0af3e9d883fde541c15a33c4dd61b5b185880e6ac3d99c423d11
deobfuscated-js PDF JavaScript deobfuscation pass 13152 bytes
Detection
ClamAV: Pdf.Exploit.Agent-35835
Obfuscation or payload: likely
Carved artifact contains 5 eval/decoder/string-building token(s). Carved artifact contains 2 long base64-like blob(s).