Malicious PDF — malware analysis report

Static analysis result for SHA-256 bf249231e2da8ea4…

MALICIOUS

PDF

43.9 KB
MD5: 755f52058dcee127edff146f2c7e8a72 SHA-1: 5ad316f465c345456220cca09c1fc76341d97e33 SHA-256: bf249231e2da8ea48361ae71563e92d2cbda3816bc0eddb3693558c16fd4e7a6
106 Risk Score

Malware Insights

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

The PDF contains obfuscated JavaScript, identified as a multi-stage dropper. This script is designed to download and execute a second-stage payload. The presence of U3D content related to CVEs also indicates a potential exploit vector. The extracted artifacts suggest a complex, multi-stage infection chain.

Heuristics 6

  • 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.
  • 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.
  • 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.
  • 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.

Extracted artifacts 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
javascript_obj0005_000.js
db89f1fdda43367cdc20f3c645038898f39e3635155bd65582f2201c482fc3ca
pdf-javascript-stream PDF /JS object 5 at offset 0x14F 672 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
f196399ac671819950ef30b5d0da55b6fe0445507c890e438b82ded7d2f66429
deobfuscated-js repeated-marker hex decoded JavaScript at offset 0x1D0C 12832 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 1 eval/decoder/string-building token(s). Carved artifact contains 1 long base64-like blob(s).
deobfuscated.js
51528f15ca67166d03c2c46c952d7f1418471dcfae8d7e793ddbd2cea138ec9c
deobfuscated-js PDF JavaScript deobfuscation pass 215442 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_off00004346.bin
fb27c6f6ffe2b08a88f79f344ef3cb4f85460ac81a062194b6fd84ab6e48b628
pdf-3d-stream PDF U3D 3D stream at offset 0x4346 28021 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact entropy is 7.79, consistent with packed or encrypted content.