Malicious PDF — malware analysis report

Static analysis result for SHA-256 f8151cf0ff802152…

MALICIOUS

PDF

11.4 KB
MD5: 88f2c378b86edb1c6b34e0655996abb2 SHA-1: 51ffb0463abf78371d28b54e608d35dc5fa5335d SHA-256: f8151cf0ff802152ee366238c3ecca87841fbaa135b969a25225108b6cbe1bcf
146 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 PowerShell T1204.001 Malicious Link T1204.002 Malicious File

The file is a PDF containing embedded JavaScript, which is flagged as malicious by ClamAV (Pdf.Exploit.Agent-36079). Static analysis identified the use of `collab.collectEmailInfo` and `String.fromCharCode`, indicating exploitation of CVE-2007-5659. The embedded JavaScript streams are heavily obfuscated, but the core functionality appears to be the execution of malicious code via this exploit.

Heuristics 6

  • Collab.collectEmailInfo — CVE-2007-5659 critical CVE exact CVE_2007_5659
    PDF JavaScript calls Collab.collectEmailInfo — CVE-2007-5659 is a buffer overflow in Adobe Reader triggered by a long argument or heap-sprayed message field passed to Collab.collectEmailInfo(). Part of a series of Acrobat JS API exploits. (identified after JavaScript deobfuscation)
  • ClamAV: Pdf.Exploit.Agent-36079 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Exploit.Agent-36079
  • JavaScript action low 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.
  • 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. (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.

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
javascript_obj0007_000.js
ef8bdac794684ae9cd4eb7091d80e1c5ca478c06c639d72d01626c1f7ce78b6d
pdf-javascript-stream PDF /JS object 7 at offset 0x19C 578 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 1 eval/decoder/string-building token(s).
legacy_pdfkit_stage_000.js
ad1537892dcdae17b2d5503b19db70bd5b3b5a1ba8a5b5e96a0896ea036ea624
deobfuscated-js repeated-marker hex decoded JavaScript at offset 0x36F 12099 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 1 long base64-like blob(s).
legacy_pdfkit_stage_001.js
1840542e3ed7080acacd10530f9c5002ed8991437d0ba15946151231c1aa772c
deobfuscated-js repeated-marker hex decoded JavaScript at offset 0x36F 4901 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 5 eval/decoder/string-building token(s).