Malicious PDF — malware analysis report

Static analysis result for SHA-256 20b16b12a60d810d…

MALICIOUS

PDF

132.6 KB
MD5: d5615932600a07558f7069048948aa39 SHA-1: a8779b105452a3cf909ebee41ede2ff04a7fa233 SHA-256: 20b16b12a60d810d73ab8c5519458d84ea8f16f670dd3a35b0c063bc2e57074f
418 Risk Score

Malware Insights

MITRE ATT&CK
T1204 Malicious Link T1204.002 Malicious File T1059.001 PowerShell T1059.007 JavaScript

The PDF file contains embedded JavaScript that utilizes a character table to obfuscate its malicious payload. This JavaScript is designed to exploit several known vulnerabilities in older versions of Adobe Reader, specifically targeting functions like media.newPlayer, Collab.getIcon, Collab.collectEmailInfo, and util.printf. The primary goal appears to be the execution of a second-stage exploit or malware, as indicated by the ClamAV detection of 'Pdf.Exploit.Agent-36388' and 'Js.Exploit.HTML-27' on extracted artifacts.

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
5d57baed9b74395485cf3e7c50d5652353fa507a9fbf85a6e86fe1123c42e7f5
pdf-javascript-stream PDF /JS object 76 at offset 0x2C2 119436 bytes
Detection
ClamAV: Js.Exploit.HTML-27
Obfuscation or payload: unlikely
char_table_stage_000.js
23893b25d21106afefae2dcfe72e0018e61f59b4edacb3a03f35f9d6d7e8443f
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).