Malicious PDF — malware analysis report

Static analysis result for SHA-256 54c1783005f21abe…

MALICIOUS

PDF

15.7 KB Authoring application: sli
MD5: 0816a2f101b69746d3b12ebd9196a339 SHA-1: a76b2daecc17af853bb1975aaf9c86aca11a1cb2 SHA-256: 54c1783005f21abe7627e6b50cb0af7bcf01868df688d2ca8f3988007c5703a9
418 Risk Score

Malware Insights

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

This PDF file contains heavily obfuscated JavaScript, identified as a large character-table eval stager. Critical heuristics indicate exploitation of multiple Adobe Reader vulnerabilities (CVE-2009-4324, CVE-2009-0927, CVE-2007-5659, CVE-2008-2992) via this JavaScript. The primary intent appears to be the execution of a second-stage payload, as suggested by the ClamAV detections on the PDF itself and an extracted artifact. The extracted JavaScript is designed to decode and execute exploit code.

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
06ec16588fcbf301f99b7f1ab0ceb106e3b2c761c78aabe079cb99857ecad80f
pdf-javascript-stream PDF /JS object 76 at offset 0x401 14858 bytes
Detection
ClamAV: Pdf.Exploit.Agent-36839
Obfuscation or payload: unlikely
array_char_table_stage_000.js
85f8f9f6f5dae5cb0f97db092f68b2c14b5d19397d26194d58554a64bc07df82
deobfuscated-js array character-table decoded JavaScript at offset 0x42D 3848 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).