Malicious PDF — malware analysis report

Static analysis result for SHA-256 83b23aac5d2ed194…

MALICIOUS

PDF

132.5 KB
MD5: bc44e5558a2bf1f434091bf7390808bd SHA-1: 27671bfd84b000557b6845bab436b975941229a2 SHA-256: 83b23aac5d2ed1946dcefc79d840abb11ae47aad33ff71e00c320571423d06ee
418 Risk Score

Malware Insights

MITRE ATT&CK
T1204.002 Malicious File T1059.001 JavaScript T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF file contains embedded JavaScript that utilizes a character-table-based eval stager to reconstruct and execute malicious code. This technique exploits several known vulnerabilities including CVE-2009-4324, CVE-2009-0927, CVE-2007-5659, and CVE-2008-2992, indicating an attempt to achieve arbitrary code execution. The extracted artifact was also flagged by ClamAV as a JavaScript exploit, further supporting the malicious intent.

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.Agent-36388 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Exploit.Agent-36388
  • 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
3aa37c4a42a16f825820a44539c163adabde9e3065e8f6ecf353fe40dce981a5
pdf-javascript-stream PDF /JS object 76 at offset 0x2C2 119291 bytes
Detection
ClamAV: Js.Exploit.HTML-27
Obfuscation or payload: unlikely
char_table_stage_000.js
5ecbb8f0930d120d32700d57a31faa4de924340ef3f71445f432181fc96b68bd
deobfuscated-js char-table indexed JavaScript (PDF /JS object 76) at offset 0x2DC 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).