Malicious PDF — malware analysis report

Static analysis result for SHA-256 5b2091d5a5550194…

MALICIOUS

PDF

17.6 KB Created: 2010-08-29 16:19:36 Authoring application: styeZek colSnap
MD5: d14b42ef03c1b4ff6b2615e76e8ff13a SHA-1: caf9ff4f2995ed44b963f7b58fe8b4473ce83288 SHA-256: 5b2091d5a5550194615b576b0f1542973a83a1f6ae6e7977a9528e496cef85f0
206 Risk Score

Malware Insights

MITRE ATT&CK
T1059.007 JavaScript T1203 Exploitation for Client Execution T1566.001 Spearphishing Attachment

This PDF document contains high-severity heuristics indicating it is malicious, including PDF_EVAL and PDF_XFA_SCRIPT firings. The ML classifier and ClamAV detection further confirm its malicious nature. The presence of embedded files, particularly 'embedded_file_obj0010.bin', suggests it is designed to drop and execute a secondary payload, likely exploiting a PDF vulnerability.

Machine Learning

  • Nyx PDF Classifier malicious score 1.0000

Heuristics 9

  • 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
  • eval() call high PDF_EVAL
    eval() found — commonly used for obfuscated exploit execution
  • 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.
  • Embedded script payload in PDF stream low 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.
  • 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_obj0008.bin
04462f810d6eacdacecc9d0a5f3f81bebc722af4415e04da19b520338f642b51
pdf-embedded-file PDF EmbeddedFile object 8 at offset 0xD7 67 bytes
embedded_file_obj0009.bin
e063279dc64f45e5fd8a3e0c526c1f12714d24c89fe2177d00853ac78ad43650
pdf-embedded-file PDF EmbeddedFile object 9 at offset 0x162 781 bytes
embedded_file_obj0010.bin
67f1098c0eb0a5d9c9f006d930fc936e8147c6cf5de99cb4d969eaa4b082315f
pdf-embedded-file PDF EmbeddedFile object 10 at offset 0x4BA 121 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 2 eval/decoder/string-building token(s).
embedded_file_obj0011.bin
9231561797a0932e91a2decf3a36bf5236fa18162700581c5bafdf3abbdaa4c9
pdf-embedded-file PDF EmbeddedFile object 11 at offset 0x57E 15008 bytes
embedded_file_obj0012.bin
6dfc2cfc739bf5cd5514e048143c782a1af7b4c86ed10bd88203471efa9b3fe7
pdf-embedded-file PDF EmbeddedFile object 12 at offset 0x4069 389 bytes
embedded_file_obj0014.bin
9f69c42e66b0c1666412737dc9cf4aa42379ee793c4ad8d07130781756ea33d5
pdf-embedded-file PDF EmbeddedFile object 14 at offset 0x4238 65 bytes
embedded_file_obj0015.bin
129e4e726ddafc353e13bd03f15fd4d48ceb50aa28924bc8b406e3be1073b46a
pdf-embedded-file PDF EmbeddedFile object 15 at offset 0x42BF 146 bytes