Malicious PDF — malware analysis report

Static analysis result for SHA-256 6879281576c176ee…

MALICIOUS

PDF

14.7 KB Created: 2009-06-06 12:30:26 +03:00 Authoring application: NitroPDF 6.0 (via BCL easyPDF 6.00.20)
MD5: cf2f07881fe5c9333090b98b897f9e53 SHA-1: a1e7029e0e7c56cb86456442803476a61a3ec738 SHA-256: 6879281576c176eed67b651cbbbc5e7d00c733a5de8dfc6f5eb2dba78ffb886e
572 Risk Score

Malware Insights

MITRE ATT&CK
T1203 Exploitation for Client Execution T1059.007 JavaScript

This PDF file contains obfuscated JavaScript that exploits multiple vulnerabilities in Adobe Reader, including CVE-2009-0927, CVE-2007-5659, and CVE-2008-2992. The script is designed to download and execute a second-stage payload from the URLs http://esli.tw/1/getexe.php and http://esli.tw. The use of multiple CVEs and a JavaScript stager indicates a sophisticated exploit kit.

Machine Learning

  • Nyx PDF Classifier malicious score 1.0000

Heuristics 15

  • 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)
  • Pidief-style multi-CVE JavaScript dispatcher critical CVE likely PDF_PIDIEF_MULTI_CVE_DISPATCH
    A single JavaScript body branches on app.viewerVersion and invokes two or more of the canonical Reader sinks (Collab.collectEmailInfo, Collab.getIcon, util.printf with a field-width format string). This is the 2009-2010 Pidief.J multi-exploit landing template: a per-version dispatcher that fires the matching CVE chain for whichever Reader version opens the file.
  • PDF JavaScript exploit cluster critical PDF_JS_EXPLOIT_CLUSTER
    PDF combines an executable JavaScript/action surface with exploit staging indicators such as eval/unescape/fromCharCode, XFA script content, or a related CVE pattern. Benign form JavaScript remains low-severity, but this correlated cluster is high-confidence malicious behavior.
  • Multi-CVE Adobe Reader JavaScript exploit kit critical PDF_ADOBE_READER_MULTI_CVE_JS_KIT
    One recovered JavaScript stage contains multiple version-gated Adobe Reader exploit branches. This is stronger evidence than independent API keywords: the PDF is selecting old Reader vulnerabilities by viewer version and running heap-sprayed Acrobat JavaScript exploit paths.
  • eval() call high PDF_EVAL
    eval() found — commonly used for obfuscated exploit execution (matched inside decoded stream)
  • Shuffled variable-fragment JavaScript stager high PDF_SHUFFLED_VAR_JOIN_JS_STAGER
    PDF JavaScript stores an exploit stage as many randomly named string fragments, rebuilds the fragment order through a name array and eval(join('+')), then decodeURIComponent/evals the result. The decoder requires a large variable table and only fires when the recovered stage contains concrete Acrobat exploit JavaScript.
  • Generic recovered JavaScript exploit stage high PDF_GENERIC_STAGE_RECOVERY
    Bounded static stage recovery exposed hidden JavaScript through generic transforms such as null-byte collapse, percent decoding, marker replacement, arithmetic character codes, fromCharCode, numeric arrays, numeric-array minus-key decoders, alphabet-index arrays, /Producer half-difference metadata arrays, hex literals, marker-stripped Base64 literals, custom 6-bit XOR table decoders, or repeated-marker hex carriers. This rule is emitted only when the recovered stage contains exploit-like Acrobat JavaScript or shellcode markers.
  • PDF JavaScript shellcode contains an embedded download URL high PDF_JS_SHELLCODE_DOWNLOAD_URL
    Decoded PDF JavaScript shellcode contains a hardcoded http(s) URL stored as little-endian %uXXXX Unicode escapes. Reader exploit shellcode embeds the second-stage fetch URL this way and pulls it down with a urlmon/URLDownloadToFile-style download-and-execute (commodity downloader behaviour rather than a specific Acrobat CVE).
  • 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.
  • PDF paints image(s) but contains no text operators info PDF_IMAGE_ONLY_LURE
    PDF has 1 image XObject(s) and the content stream contains no text-emitting operators (BT/ET, Tj, TJ, ', ") in either raw bytes or decompressed streams — this is the screenshot-as-PDF pattern used to bypass text-based scanners and to deliver instructions purely through rendered pixels. It is informational unless paired with invisible links or risky URI context.
  • 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.
  • Embedded URL info EMBEDDED_URL
    One or more URLs were extracted from the document. The URL itself is not a detection — see the per-URL labels for which channel (macro, JS, link annotation, document body, ...) reached each URL.
    URL http://esli.tw/1/getexe.php
    • http://esli.tw

Extracted artifacts 6

Files carved from inside the sample during analysis.

FilenameKindSourceSize
javascript_obj0015_000.js
6d4891c90e3cd302cd50df37dce64d33c2d920bcf54b46b355c35e77b4c5bce5
pdf-javascript-stream PDF /JS object 15 at offset 0x315 28629 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 2 eval/decoder/string-building token(s).
shuffled_var_join_stage_000.js
1f8688b8a6b8b4e8d7feadcdb830536cab9b66f7c6e5b3277f834981827338eb
deobfuscated-js shuffled variable-fragment join decoded JavaScript object 15 at offset 0x4A6D 4909 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 7 eval/decoder/string-building token(s).
shuffled_var_join_stage_001.js
575f95dc7e142cdb80f553f84bd6ab57d37ce9cda2d4ed609e16acdfd1b1268f
deobfuscated-js shuffled variable-fragment join decoded JavaScript object 15 at offset 0x4291 5305 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 7 eval/decoder/string-building token(s).
shuffled_var_join_stage_002.js
05c5698683fe3ae70cc570b629b8d2a51f6802fc1b6a83629498e5d9859862f1
deobfuscated-js shuffled variable-fragment join decoded JavaScript object 15 at offset 0x4291 4907 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 7 eval/decoder/string-building token(s).
generic_stage_recovery_000.js
a219d2dbb97b2ea0517991956f3253abd9247c0f1ea9f2769a3754cc370e931d
deobfuscated-js generic stage recovery percent-decode from JavaScript object 15 at offset 0x315 26617 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 3 eval/decoder/string-building token(s).
generic_stage_recovery_001.js
518aa1036afd9be4ec423c91dcf3c430b0373bd792c0cb24beb7014a9760e468
deobfuscated-js generic stage recovery percent-decode -> percent-decode from JavaScript object 15 at offset 0x315 26615 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 3 eval/decoder/string-building token(s).