Malicious PDF — malware analysis report

Static analysis result for SHA-256 afb455adcbbdbb6f…

MALICIOUS

PDF

6.8 KB
MD5: 41998c0883bdde5f8f2eecfadc64e3a9 SHA-1: e1a8cfec56362c93f254464a3c85eb84590f93a1 SHA-256: afb455adcbbdbb6fb9cc168d121f0a9acea4bb3a446e710ae7522903d838a5ba
266 Risk Score

Malware Insights

MITRE ATT&CK
T1204.002 Malicious File T1059.001 JavaScript/JScript

The PDF file contains multiple critical heuristic firings indicating exploitation of CVE-2009-4324, CVE-2009-0927, and CVE-2007-5659 through embedded JavaScript. The JavaScript is XOR-decoded and obfuscated, but analysis of extracted artifacts reveals it is designed to download and execute a second-stage payload, as indicated by the ClamAV detection 'Js.Exploit.Shellcode-18'. The file's purpose is to compromise the user's system via these exploits.

Heuristics 8

  • media.newPlayer — CVE-2009-4324 critical CVE exact CVE_2009_4324
    PDF JavaScript calls media.newPlayer — CVE-2009-4324 is a use-after-free in Adobe Reader's multimedia plugin triggered by media.newPlayer(). Actively exploited as a zero-day in December 2009. (identified after JavaScript deobfuscation)
  • 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)
  • 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.
  • 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_obj0039_000.js
859a8a074ea7af611887a538ce49120838766bb771e1ee5afca10eca47b40fbc
pdf-javascript-stream PDF /JS object 39 at offset 0x16F 21750 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
e71bce33d303a704db1ae7ac3ddcdedcf008ba987e73a469e26089921d570909
deobfuscated-js numeric array XOR decoded JavaScript at offset 0x16F 5380 bytes
Detection
ClamAV: Js.Exploit.Shellcode-18
Obfuscation or payload: likely
Carved artifact contains 9 eval/decoder/string-building token(s).
legacy_pdfkit_stage_001.js
727b0fc42b667c4cb740f65b825b0efdab30bc0d51f47e0485476a97e370454c
deobfuscated-js numPages XOR decoded JavaScript at offset 0x16F 5380 bytes