Malicious PDF — malware analysis report

Static analysis result for SHA-256 a3fa4d8d936c8cd8…

MALICIOUS

PDF

173.5 KB Created: 2009-07-07 21:23:42 +08:00
MD5: 4321d341f31dc7f427fb395bac3db133 SHA-1: 1da0a3e98a5be80a5e6c4f1209f7d206995e0ca7 SHA-256: a3fa4d8d936c8cd843f654415c3457af1694f76bd6d016185c5525a54047fc4a
226 Risk Score

Malware Insights

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

The PDF contains an embedded JavaScript stream which utilizes `eval()` and `unescape()` functions, indicating obfuscated code execution. ClamAV detection as 'Pdf.Exploit.Agent-35646' strongly suggests exploitation of a known PDF vulnerability. The primary IOC is the extracted JavaScript file, which is likely responsible for the malicious payload delivery.

Heuristics 9

  • ClamAV: Pdf.Exploit.Agent-35646 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Exploit.Agent-35646
  • 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)
  • unescape() call high PDF_UNESCAPE
    unescape() found — often used to decode shellcode in PDF JS exploits (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. (matched inside decoded stream)
  • 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. (matched inside decoded stream)
  • Embedded file low PDF_EMBEDDED
    PDF embeds a file attachment — could carry an executable or another weaponised document as a nested payload (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.
  • Embedded URL info EMBEDDED_URL
    One or more URLs were extracted from the document. The URL itself is not a detection — see the per-URL labels for which channel (macro, JS, link annotation, document body, ...) reached each URL.
    URL http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://ns.adobe.com/xap/1.0/
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/pdf/1.3/

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
stream_004_off00000674.js
2c80bdd3d6b91ebbda4509cf43bc8591224ecc61f53e390b523a7f4ae7dbdfe7		 decompressed-pdf-stream PDF FlateDecoded stream at offset 0x674 5027 bytes
Detection
ClamAV: Pdf.Exploit.Agent-35646
Obfuscation or payload: likely
Carved artifact contains 5 eval/decoder/string-building token(s).
objstm_0026_00.bin
9c0baebce7553b4739cd2cb1428834b48d2da40c9481814818257322b116307a		 pdf-objstm-decoded PDF /ObjStm 26 0 obj (inflated) 306 bytes

Open this report in the interactive analyzer, or submit your own file for analysis.