Malicious PDF — malware analysis report

Static analysis result for SHA-256 dc0b9c37200607db…

MALICIOUS

PDF

102.1 KB
MD5: aa9a90380b0492877061c1a956142e9e SHA-1: 8656ddab17291a1eddac23b9ec1b4c6f2ea6f2c1 SHA-256: dc0b9c37200607dbdbb95282ba46940318136be6cffb22da65c888dfd0b8d94a
418 Risk Score

Malware Insights

MITRE ATT&CK
T1204.002 Malicious File: User Execution T1059.001 Command and Scripting Interpreter: JavaScript

The PDF file contains embedded JavaScript that utilizes character-table indexing to obfuscate its functionality. Critical heuristics indicate exploitation of multiple Adobe Reader vulnerabilities (CVE-2009-4324, CVE-2009-0927, CVE-2007-5659, CVE-2008-2992). The deobfuscated JavaScript is identified as a stager, strongly suggesting its purpose is to download and execute a secondary malicious payload. ClamAV detections further confirm the malicious nature of the file and its extracted components.

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.Trojan.Agent-36936 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Trojan.Agent-36936
  • 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.
  • Character-table JavaScript eval stager high PDF_JS_CHAR_TABLE_EVAL_STAGER
    PDF JavaScript reconstructs an exploit stage by indexing into a small character table, appending hundreds of one-character fragments, joining the array, and evaluating the result. This static fallback fires only after the bounded decoder recovers an exploit-like stage, so it catches this obfuscation even when no single CVE API signature is available.
  • 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
7827b82e6d1e4180822fa0a7cda60e03560d944efede8658dc63559e34e95936
pdf-javascript-stream PDF /JS object 76 at offset 0x2C2 95903 bytes
Detection
ClamAV: Js.Exploit.HTML-29
Obfuscation or payload: unlikely
char_table_stage_000.js
0c73e750cb5468a6c103dcd2926ade4fb660750fa0896639b266d3b0e7882d4b
deobfuscated-js char-table indexed JavaScript (PDF /JS object 76) at offset 0x2FB 3858 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).