Malicious PDF — malware analysis report

Static analysis result for SHA-256 a1989cb9df7a4bb0…

MALICIOUS

PDF

13.4 KB Created: 2010-08-29 16:19:36 Authoring application: styeZek colSnap
MD5: 11b7bf7c5f6484e200ba39bad07c0a0a SHA-1: 0873fcc6f8790214c9db18f1126a4aeb4c1d5007 SHA-256: a1989cb9df7a4bb0d77d8208d9f07188322fd03ac5e3878c2c243418d01c066b
138 Risk Score

Malware Insights

MITRE ATT&CK
T1204 Malicious Link T1204.002 Malicious Link: Malicious File T1059 Command and Scripting Interpreter T1059.001 Command and Scripting Interpreter: PowerShell

The PDF file contains embedded scripts and is flagged by multiple heuristics, including a critical ClamAV detection for 'Pdf.Exploit.Dropped-81' and an ML classifier indicating maliciousness. The presence of embedded files and the use of 'String.fromCharCode' suggest an attempt to obfuscate malicious code. The primary attack vector appears to be exploiting a PDF vulnerability to download and execute a secondary payload, as indicated by the 'PDF_EMBEDDED_SCRIPT_PAYLOAD' and 'EXTRACTED_FILE_STATIC_TRIAGE' heuristics.

Machine Learning

  • Nyx PDF Classifier malicious score 1.0000

Heuristics 8

  • 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.
  • PDF differential parser failed info PDF_DIFFERENTIAL_PARSE_FAILED
    The cross-check parser (pdfminer.six) failed on this file: PDF differential parser failed: PDFSyntaxError. Static heuristics still ran and any of their findings above are valid; only the differential cross-check signal is missing.
  • 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://www.xfa.org/schema/xfa-template/2.5/
    • http://ns.adobe.com/xtd/
    • http://www.xfa.org/schema/xfa-data/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_obj0006.bin
d81baa73e490e4cb879e13927cacd1dd1be37524a37eac51603e15117c578777		 pdf-embedded-file PDF EmbeddedFile object 6 at offset 0x21C 84 bytes
embedded_file_obj0007.bin
24c130f03a4cf51d470b536e94c1e58af67665739e200e0ce198ad41086243c0		 pdf-embedded-file PDF EmbeddedFile object 7 at offset 0x2BE 228 bytes
embedded_file_obj0008.bin
47460ef0a137c9d7a50eb5a05d39a54bdfc589c1267f5a7d9d5cf5b1d69a0911		 pdf-embedded-file PDF EmbeddedFile object 8 at offset 0x3E4 1303 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 1 eval/decoder/string-building token(s).
embedded_file_obj0009.bin
c97e0522381d6196cc0695f35f4d065f15c9c86a9601a7f776c6afd3f4c6b460		 pdf-embedded-file PDF EmbeddedFile object 9 at offset 0x949 199 bytes
embedded_file_obj0010.bin
508b18395d7f1caa7a2503039020608aa25c4cd4f84ad633b96426d12dd3619e		 pdf-embedded-file PDF EmbeddedFile object 10 at offset 0xA61 9726 bytes
embedded_file_obj0011.bin
e6c26a3478346d27e841ad49868ebf68bf4c6863b6750e8d60bda3c4c6f79876		 pdf-embedded-file PDF EmbeddedFile object 11 at offset 0x30AD 77 bytes
embedded_file_obj0012.bin
92a3ce61d783e15932b5de127ce45a9b4c2f98f4da2453f65241573c1dda808a		 pdf-embedded-file PDF EmbeddedFile object 12 at offset 0x3148 56 bytes

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