PDF malware analysis — malicious · d3fc339a37378c19

MALICIOUS

PDF

44.3 KB

MD5: dacb6c7c3e76e73a8b7e2a49c97184dc SHA-1: 8499c2ddda72e148db486f3008c65c0b444d92a0 SHA-256: d3fc339a37378c199ca297f1772685cb01783a90514ebec1db6047beb9abbe43

136 Risk Score

Malware Insights

MITRE ATT&CK

T1059.001 PowerShell T1566.002 Spearphishing Attachment T1204.002 Malicious File

This PDF file exhibits high confidence maliciousness, primarily due to its use of obfuscated JavaScript. The heuristics indicate a multi-stage dropper mechanism, where the embedded JavaScript is designed to deobfuscate and execute a secondary payload. The presence of multiple extracted JavaScript files and a U3D stream further supports this dropper functionality. The ML classifier strongly flags this as malicious, and the overall pattern suggests a sophisticated attempt to bypass security measures and deliver further malware.

Machine Learning

Nyx PDF Classifier malicious score 1.0000

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.

Filename	Kind	Source	Size
`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` `596a05d9fdf26643829609a3729b7457166dff9f6711f608ce84380a9774892a`	deobfuscated-js	repeated-marker hex decoded JavaScript at offset 0x1DCD	13221 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` `ed75ac97ce91807118f326a72fb4a3f0989799f8bad9ba1ba92c94bd844ce5bc`	deobfuscated-js	PDF JavaScript deobfuscation pass	299450 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_off000044cf.bin` `fb27c6f6ffe2b08a88f79f344ef3cb4f85460ac81a062194b6fd84ab6e48b628`	pdf-3d-stream	PDF U3D 3D stream at offset 0x44CF	28021 bytes
Detection ClamAV: No threats found Obfuscation or payload: likely Carved artifact entropy is 7.79, consistent with packed or encrypted content.

Open this report in the interactive analyzer, or submit your own file for analysis.