Malicious PDF — malware analysis report

Static analysis result for SHA-256 5245362fab416f20…

MALICIOUS

PDF

7.9 KB
MD5: e201394ac7e7c53775f9f003e481051f SHA-1: 144eab42955fcaa20b7d7756d7040beb97b46d1f SHA-256: 5245362fab416f203fe8084ed85e4abc5a164610ae000ebb3d758886e1e9df4e
346 Risk Score

Malware Insights

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

The PDF file contains embedded JavaScript that utilizes custom Base64 decoding and eval() calls to unpack and execute exploit code targeting Adobe Reader. Critical heuristics indicate exploitation of CVE-2009-0927, CVE-2007-5659, and CVE-2008-2992. An extracted artifact was detected by ClamAV as Js.Exploit.Shellcode-18, confirming the malicious nature of the script. The script's primary intent is to download and execute a second-stage payload.

Heuristics 10

  • Collab.getIcon — CVE-2009-0927 critical CVE exact CVE_2009_0927
    PDF JavaScript calls Collab.getIcon — CVE-2009-0927 is a stack buffer overflow in Adobe Reader triggered by Collab.getIcon() with a crafted argument. Allows arbitrary code execution. (identified after JavaScript deobfuscation)
  • 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)
  • util.printf — CVE-2008-2992 critical CVE exact CVE_2008_2992
    PDF JavaScript calls util.printf() — CVE-2008-2992 is a stack buffer overflow in Adobe Reader triggered by a long format-specifier argument. Widely exploited in the wild after disclosure. (identified after JavaScript deobfuscation)
  • ClamAV detection on extracted artifact critical EXTRACTED_FILE_CLAMAV
    ClamAV flagged at least one file extracted from inside this sample. Even when the wrapping document carries no AV detection of its own, a hit on the carved artifact is a strong indicator the sample is a delivery vehicle.
  • OpenAction trigger high PDF_OPENACTION
    PDF has an /OpenAction — code runs automatically when opened
  • eval() call high PDF_EVAL
    eval() found — commonly used for obfuscated exploit execution (matched inside decoded stream)
  • 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 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
javascript_obj0009_000.js
cb0c57f3ac58a18994cdb36bee23f825765a8353ad8a3642b1c885ac313a02a5
pdf-javascript-stream PDF /JS object 9 at offset 0xD6 19616 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 4 eval/decoder/string-building token(s). Carved artifact contains 1 long base64-like blob(s).
custom_b64_stage_000.js
9cfa92feaede6871fe5ea613581530b2b56e5f79b4de6771cd535b3d8fd2b94b
deobfuscated-js custom Base64 decoded JavaScript layer 2 (PDF /JS object 9) at offset 0x436 10527 bytes
Detection
ClamAV: Js.Exploit.Shellcode-18
Obfuscation or payload: likely
Carved artifact contains 9 eval/decoder/string-building token(s).