Malicious PDF — malware analysis report

Static analysis result for SHA-256 79577900c2f3b101…

MALICIOUS

PDF

8.1 KB First seen: 2013-04-07
MD5: b7cd334039ed70783b5fc5217b7ffc78 SHA-1: 14fa99397361398a599d45bbb771ff1e7b01a5a0 SHA-256: 79577900c2f3b101c66b3edd235c6a894c0a6c3c71748e8305e0fc8219179cbc
158 Risk Score

Malware Insights

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

The PDF sample contains embedded JavaScript that utilizes String.fromCharCode and eval() for obfuscation. This script is designed to download and execute a second-stage payload from the URL http://d2F.QK/_-a. The ML classifier strongly indicates maliciousness, and the combination of JavaScript execution and external URL contact points to a downloader or exploit delivery mechanism.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9224

Heuristics 5

  • JavaScript action low 2 related findings 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)
  • PDF JavaScript exploit cluster critical PDF_JS_EXPLOIT_CLUSTER
    PDF combines an executable JavaScript/action surface with exploit staging indicators such as eval/unescape/fromCharCode, XFA script content, or a related CVE pattern. Benign form JavaScript remains low-severity, but this correlated cluster is high-confidence malicious behavior.
    Matched line in script
    eval(o);
  • 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)
  • 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://d2F.QK/_-a Referenced by PDF JavaScript
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In PDF document text
    • http://ns.adobe.com/xap/1.0/In PDF document text
    • http://purl.org/dc/elements/1.1/In PDF document text
    • http://ns.adobe.com/xap/1.0/mm/In PDF document text
    • http://ns.adobe.com/pdf/1.3/In PDF document text
🗂 Part of campaign: d2f.qk 21 samples

Related samples 8

Ranked by shared artifacts, heuristics, extracted URLs, CVEs, and signatures.

Full JSON: related samples API

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
stream_002_off00000328.bin decompressed-pdf-stream PDF FlateDecoded stream at offset 0x328 2997 bytes
SHA-256: 143663f67efeddcc3c12961508d245809f72f83a9744b9baac5b3def18d88284
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 1 eval/decoder/string-building token(s).
objstm_0024_00.bin pdf-objstm-decoded PDF /ObjStm 24 0 obj (inflated) 380 bytes
SHA-256: 64d31ee0bbda581dee1303a32fe5211744a2088944541e3dfa1af3c9f3aa6d3a

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