Malicious PDF — malware analysis report

Static analysis result for SHA-256 6fb28a0e8a7c44bd…

MALICIOUS

PDF

35.7 KB
MD5: be6091bcd3cd8dda7b2f25d265dcc92a SHA-1: 67aa488144c16b60c5c14e51d5ef47ba19fac1e3 SHA-256: 6fb28a0e8a7c44bd8c3bd73c03918fd0aeb786858895690f9dce4537d3cd8988
606 Risk Score

Malware Insights

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

This PDF exploits multiple Adobe Reader vulnerabilities (CVE-2009-3459, CVE-2007-5659) to execute embedded JavaScript. The JavaScript is obfuscated and attempts to download a second-stage payload from the URL http://gowinse.info/cgi-bin/rtm/z00a106201r0409R52cbb274X0ac6f8c9Y41548042Z0100f080. The presence of multiple exploit-related heuristics and the embedded URL strongly indicate a malicious dropper.

Machine Learning

  • Nyx PDF Classifier malicious score 1.0000

Heuristics 17

  • Adobe Reader U3D auto-activated 3D annotation — CVE-2009-3459 critical CVE likely CVE_2009_3459_U3D_AUTOACTIVATE
    PDF contains a /Subtype /3D annotation that is configured to auto-activate on page view (/3DA <</A /PV /AIS /I>>) alongside a /U3D stream and JavaScript. This is the document shape used by CVE-2009-3459 (Adobe Reader U3D CLODProgressiveMeshDeclaration heap overflow, APSB09-15): the U3D parser runs without any user interaction once the page is rendered, while the accompanying JavaScript prepares a heap-spray to land controlled memory inside the corrupted allocation.
  • 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)
  • Adobe Reader U3D CLODProgressiveMeshDeclaration exploit critical CVE likely CVE_2009_3953
    PDF combines malformed U3D 3D content with JavaScript/action activation. CVE-2009-3953 is an Adobe Reader/Acrobat U3D CLODProgressiveMeshDeclaration array-boundary vulnerability triggered by malformed U3D data in a PDF.
  • U3D/3D content in PDF — Adobe Reader 3D parser CVE-family indicator high CVE related PDF_U3D_CVE_RELATED
    PDF contains U3D (Universal 3D) or 3D annotation content — CVE-2011-2462 and CVE-2009-3953 are critical vulnerabilities in Adobe Reader's U3D processing that allow arbitrary code execution. U3D content in PDFs is extremely rare in normal documents.
  • Adobe Reader APSB09-15 patch-range version gate (CVE-2009-3459) high CVE likely PDF_JS_ADOBE_APSB09_15_PATCH_GATE
    PDF JavaScript gates the exploit payload on an Adobe Reader version range that exactly matches the APSB09-15 patch boundary (< 9.2, < 8.1.7, < 7.1.4). That boundary fingerprints the CVE-2009-2990 / CVE-2009-3459 U3D parser vulnerabilities — no benign script tests all three Reader version-points together.
  • Adobe Reader APSB08-13 patch-range version gate (CVE-2007-5659) high CVE likely PDF_JS_ADOBE_APSB08_13_PATCH_GATE
    PDF JavaScript gates the exploit payload on (>= 8 && < 8.1.1) OR (< 7.1) — the Reader 7.0.x / 8.0–8.1.1 window patched by Adobe APSB08-13 for the CVE-2007-5659 Collab.collectEmailInfo buffer overflow. Only kits that target that exact bug check both of those patch points; benign scripts do not.
  • 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.
  • ClamAV: Pdf.Dropper.Agent-1828789 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Dropper.Agent-1828789
  • 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.
  • Obfuscated multi-stage PDF JavaScript dropper high PDF_JS_OBFUSCATED_DROPPER
    PDF JavaScript shows 3 independent signals of exploit-kit-style multi-stage obfuscation: annot_subject_stage, hex_dashed_payload, repeated_pluginschk. This is strongly consistent with pre-2011 Adobe Reader PDF droppers — OpenAction JS reads encoded data from annotation subjects, decodes it through one or more hex / base-N loops, and invokes eval indirectly (method name built one character at a time). The actual CVE is hidden in the final decoded layer and is not visible via static analysis.
  • 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.
  • String.fromCharCode low PDF_FROMCHARCODE
    String.fromCharCode found — used to construct payload strings dynamically. Common in benign JavaScript libraries for codepoint manipulation, so this alone is informational; weaponised use is also caught by the dedicated fromCharCode-stage and exploit-shape rules. (matched inside decoded stream)
  • syncAnnotScan annotation-staging primitive low PDF_FOXIT_SYNCANNOTSCAN
    PDF JavaScript calls syncAnnotScan() — a no-op annotation-enumeration primitive used by exploit-kit JavaScript to stage payload reads from annotation /Subject fields before eval(). Not a vulnerable sink itself; rarely seen in legitimate PDFs. (matched in decompressed stream)
  • 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://gowinse.info/cgi-bin/rtm/z00a106201r0409R52cbb274X0ac6f8c9Y41548042Z0100f080

Extracted artifacts 6

Files carved from inside the sample during analysis.

FilenameKindSourceSize
javascript_obj0005_000.js
9d5c7e01faed5b04e9ec11f1d98b73f0012c871beaf60e9f9d32ad6df00d46f7
pdf-javascript-stream PDF /JS object 5 at offset 0x14F 550 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 1 eval/decoder/string-building token(s).
generic_stage_recovery_000.js
f4775ec9df865063984a555e0731e5ff26e73ddb98c144fce7fab43f6ef2965c
deobfuscated-js generic stage recovery split-literal-normalize from JavaScript object 5 at offset 0x14F 545 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 1 eval/decoder/string-building token(s).
legacy_pdfkit_stage_000.js
0fd30cc5b3d60ee0aef4ed7b319b5fbec84c431c104e7d0db56804f53ae13dd1
deobfuscated-js repeated-marker hex decoded JavaScript at offset 0x1D7E 1752 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 1 eval/decoder/string-building token(s).
legacy_pdfkit_stage_001.js
1c7b01f17d647d937bc6af32e2281338ec28f91c6d059d2de30db99047182e7a
deobfuscated-js annotation-subject callee-key decoded JavaScript at offset 0x360 5472 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 5 eval/decoder/string-building token(s).
deobfuscated.js
09afe9fe1766881784c74fe0e1987955c51dfe3f92e7f9431f7f2005c0703a2b
deobfuscated-js PDF JavaScript deobfuscation pass 179466 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 2 eval/decoder/string-building token(s). Carved artifact contains 1 long base64-like blob(s).
u3d_00_off00002260.bin
70cf2aead4823e6d2651c9281eed0aa967449da358f439efb9e8e707421175e0
pdf-3d-stream PDF U3D 3D stream at offset 0x2260 28021 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact entropy is 7.79, consistent with packed or encrypted content.