Malicious PDF — malware analysis report

Static analysis result for SHA-256 c043a7c5654b7450…

MALICIOUS

PDF

17.3 KB Created: 2010-08-29 16:19:36 Authoring application: styeZek colSnap
MD5: a8b915a5e518627f55d661ee81b34f10 SHA-1: f87734824a86c9a0e2d92541c25296ba10f08829 SHA-256: c043a7c5654b7450198038bf7c02e4ef6f3d7ffdb5df82fcf4b4659e6bbec09d
176 Risk Score

Malware Insights

MITRE ATT&CK
T1204.002 Malicious File T1059.001 PowerShell T1105 Ingress Tool Transfer

The PDF file contains embedded scripts and is flagged by multiple high-severity heuristics, including ClamAV detection for 'Pdf.Exploit.Dropped-81'. The presence of an embedded script payload and XFA form with risky executable script indicates an attempt to exploit vulnerabilities. The ML classifier also strongly suggests maliciousness. The primary IOC is the embedded file 'embedded_file_obj0012.bin', which likely contains the secondary payload.

Machine Learning

  • Nyx PDF Classifier malicious score 1.0000

Heuristics 8

  • XFA form contains risky executable script high CVE related PDF_XFA_SCRIPT
    PDF embeds an XFA form whose script block contains exploit, submission/launch, or shell-execution primitives. Ordinary LiveCycle print/update scripts are left as generic XFA/JS signals unless stronger behavior is present.
  • ClamAV: Pdf.Exploit.Dropped-81 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Exploit.Dropped-81
  • Embedded script payload in PDF stream medium PDF_EMBEDDED_SCRIPT_PAYLOAD
    PDF stream bytes contain an HTML/XFA <script> tag without accompanying Windows shell-execution primitives — common in accessible XFA forms but worth surfacing for analyst review.
  • Embedded file low PDF_EMBEDDED
    PDF embeds a file attachment — could carry an executable or another weaponised document as a nested payload
  • XFA form low PDF_XFA
    PDF uses XML Forms Architecture — can contain script logic
  • 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.
  • 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://ns.adobe.com/xdp/
    • http://www.xfa.org/schema/xci/1.0/
    • http://ns.adobe.com/xfdf/
    • http://www.xfa.org/schema/xfa-form/2.8/

Extracted artifacts 7

Files carved from inside the sample during analysis.

FilenameKindSourceSize
embedded_file_obj0008.bin
d81baa73e490e4cb879e13927cacd1dd1be37524a37eac51603e15117c578777
pdf-embedded-file PDF EmbeddedFile object 8 at offset 0xDB 84 bytes
embedded_file_obj0009.bin
24c130f03a4cf51d470b536e94c1e58af67665739e200e0ce198ad41086243c0
pdf-embedded-file PDF EmbeddedFile object 9 at offset 0x176 228 bytes
embedded_file_obj0010.bin
9ccb532c112970b6715e79f8d0b32dd3cc3bf4d5fad7a6e4ae23562471f646ee
pdf-embedded-file PDF EmbeddedFile object 10 at offset 0x2B8 991 bytes
embedded_file_obj0011.bin
c97e0522381d6196cc0695f35f4d065f15c9c86a9601a7f776c6afd3f4c6b460
pdf-embedded-file PDF EmbeddedFile object 11 at offset 0x53C 199 bytes
embedded_file_obj0012.bin
af448c64e9d0fbd15c4abb9bcec364410a43526f6d07662660d2b46e68fe74a2
pdf-embedded-file PDF EmbeddedFile object 12 at offset 0x62E 34221 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 1 eval/decoder/string-building token(s).
embedded_file_obj0013.bin
e6c26a3478346d27e841ad49868ebf68bf4c6863b6750e8d60bda3c4c6f79876
pdf-embedded-file PDF EmbeddedFile object 13 at offset 0x40CA 77 bytes
embedded_file_obj0014.bin
92a3ce61d783e15932b5de127ce45a9b4c2f98f4da2453f65241573c1dda808a
pdf-embedded-file PDF EmbeddedFile object 14 at offset 0x415E 56 bytes