Malicious PDF — malware analysis report

Static analysis result for SHA-256 f7997c43a4b5b37c…

MALICIOUS

PDF

15.8 KB Authoring application: sli
MD5: f7db3697a9bf5953df297e35188e33ee SHA-1: 3d7307f67fa228947ce688bd7a208cd8476ffe38 SHA-256: f7997c43a4b5b37cf287c86b908495ca37aee6b1c0238c1c3ed3234093dca389
418 Risk Score

Malware Insights

MITRE ATT&CK
T1204 Malicious Link T1204.001 Malicious Link: Malicious Link T1059.001 Command and Scripting Interpreter: PowerShell T1059.007 Command and Scripting Interpreter: JavaScript

The PDF file contains obfuscated JavaScript that utilizes character-table decoding to exploit multiple known Adobe Reader vulnerabilities including CVE-2009-4324, CVE-2009-0927, CVE-2007-5659, and CVE-2008-2992. This JavaScript stager is designed to download and execute a second-stage payload, as indicated by ClamAV detections on the sample and an extracted artifact. The primary attack pattern is the exploitation of these vulnerabilities to achieve arbitrary code execution.

Heuristics 10

  • 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)
  • 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: Pdf.Exploit.Dropped-91 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Exploit.Dropped-91
  • 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.
  • Large character-table JavaScript eval stager high PDF_JS_LARGE_CHAR_TABLE_EVAL_STAGER
    PDF JavaScript contains a large numeric index array, a short character table, an indirect eval sink, and a long loop that reconstructs a hidden stage. This is an exploit-kit staging technique even when the recovered first stage is still encoded.
  • 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.
  • 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_obj0076_000.js
f52513b8dfe3dac32b84a159c52b34d966656cfc4c87b9060ce4499c187bf19d
pdf-javascript-stream PDF /JS object 76 at offset 0x3FE 14937 bytes
Detection
ClamAV: Pdf.Exploit.Agent-36839
Obfuscation or payload: unlikely
array_char_table_stage_000.js
50e20971c1415b2b06efc2e04cf5dab008c7f0d92da649b8a24c732d7fd111a3
deobfuscated-js array character-table decoded JavaScript at offset 0x42A 3878 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 11 eval/decoder/string-building token(s). Carved artifact contains 1 long base64-like blob(s).