Nemucod PDF malware analysis — malicious · 7cd25bd59bcb09cd

MALICIOUS

PDF

53.7 KB Authoring application: PyPDF2

MD5: d78f7121fb68dade712e2e284bc6864f SHA-1: 7fd845be56590db033ca40656f240fb3d416992f SHA-256: 7cd25bd59bcb09cdb85bba1dd7be6f012a903e61674c4fa7afe2dec2d8f8a12b

254 Risk Score

Malware Insights

Nemucod · confidence 95%

MITRE ATT&CK

T1059.001 PowerShell T1204.002 Malicious File

This PDF file was flagged by ClamAV as Txt.Downloader.Nemucod-6769573-0, indicating it belongs to the Nemucod family. The file contains embedded JavaScript with eval() calls, which is a common technique for obfuscating malicious code. The extracted JavaScript artifacts suggest the script is designed to download and execute a second-stage payload, consistent with Nemucod's typical behavior.

Machine Learning

Nyx PDF Classifier malicious score 0.9791

Heuristics 7

ClamAV: Txt.Downloader.Nemucod-6769573-0 critical CLAMAV_DETECTION

ClamAV detected this file as malware: Txt.Downloader.Nemucod-6769573-0
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.
eval() call high PDF_EVAL

eval() found — commonly used for obfuscated exploit execution
Suspicious extracted artifact high 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.
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.
AcroForm button with action trigger low PDF_ACROFORM_BUTTON

PDF contains a /Btn form field together with a SubmitForm/URI/Launch/JS trigger — this is the building block of fake 'Download' or 'Open' button overlays used in PDF phishing lures

Extracted artifacts 4

Files carved from inside the sample during analysis.

Filename	Kind	Source	Size
`javascript_obj0005_000.js` `48aa8bcc82df7b333795ae6db3e554c300d79350aa8c8bb652945b73d72afe73`	pdf-javascript-stream	PDF /JS object 5 at offset 0x31F	13227 bytes
Detection ClamAV: Txt.Downloader.Nemucod-6769573-0 Obfuscation or payload: likely Carved artifact contains 26 eval/decoder/string-building token(s).
`legacy_pdfkit_stage_000.js` `2b76a1288d121adb02c83b3f7cdb030b7a19047c592e3a9522025bc2e2314459`	deobfuscated-js	split-join delimiter stripped JavaScript at offset 0x3D6	7002 bytes
Detection ClamAV: No threats found Obfuscation or payload: likely Carved artifact contains 8 shell/COM execution token(s). Carved artifact contains 27 eval/decoder/string-building token(s).
`legacy_pdfkit_stage_001.js` `0d10b404e45c9123e59198495fe3ce3db6574117400659dcabae2dd2063521e1`	deobfuscated-js	split-join delimiter stripped JavaScript at offset 0x369	54812 bytes
Detection ClamAV: Txt.Downloader.Nemucod-6769573-0 Obfuscation or payload: likely Carved artifact contains 26 eval/decoder/string-building token(s).
`legacy_pdfkit_stage_002.js` `de246a5ec82bd3df99e9a6b5659b1ec78124c87792b87e89b231cd9c5e94681b`	deobfuscated-js	split-join delimiter stripped JavaScript at offset 0x404	48615 bytes
Detection ClamAV: No threats found Obfuscation or payload: likely Carved artifact contains 8 shell/COM execution token(s). Carved artifact contains 27 eval/decoder/string-building token(s).

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