Malicious PDF — malware analysis report

Static analysis result for SHA-256 21cda62c696a8d64…

MALICIOUS

PDF

71.4 KB Created: 2021-09-25 08:14:09 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: b80a984d4f321f46e1d11f22ab261530 SHA-1: bcfe18743fdcdfc332e3c0f527b9f979ff3677f5 SHA-256: 21cda62c696a8d64f6baa6e6f73704ea02c85a4cd5f951f6707ae75b9cd4a4e8
134 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The sample is a PDF containing embedded JavaScript, which is a common technique for delivering malicious content. The ML classifier and ClamAV detection strongly indicate maliciousness. The embedded JavaScript likely executes to redirect the user to one of the numerous external URLs found in the document, potentially for phishing or to download a second-stage payload.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • Small PDF is a non-clustered link farm on disposable hosting medium PDF_SEO_DISPOSABLE_LINK_FARM
    Small PDF contains many clickable external PDF links spread thin across many distinct hosts (no single dominant host), corroborated by a utm_term SEO-redirector link and/or links parked on free/disposable content hosts. This is the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains, rather than a normal document citation pattern. The PDF itself carries no exploit — the risk is the linked destinations.
  • 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.
  • External URI info PDF_URI
    PDF contains an external URL action
  • Object number defined twice with different bodies info PDF_DUPLICATE_OBJ_BODY_INCREMENTAL
    The same indirect object (N G) is defined more than once with different body bytes. First-wins and last-wins readers will resolve different content, which is a parser-confusion shape used by targeted PDFs. Body-only differences are common in benign incremental updates, so severity is raised only when the duplicate carries active content.
  • 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 https://rockeit.com/userfiles/file/76884332049.pdf In PDF document text
    • http://flooroverstock.com/admin/userfiles/file/diwekezev.pdfIn PDF document text
    • http://www.fullertherapy.com/wp-content/plugins/formcraft/file-upload/server/content/files/161363fd51607e---vigunujoguxumafetuxijej.pdfIn PDF document text
    • https://t-groupvnxkld.com/uploads/news_file/26643274835.pdfIn PDF document text
    • http://guide-eq.com/userfiles/file/20210924181430_m0gmws.pdfIn PDF document text
    • http://amindoost.ir/images/upload/files/98476432279.pdfIn PDF document text
    • http://mastervgtour.by/var/upload/file/17970360061.pdfIn PDF document text
    • http://christembassydocklands.org/wp-content/plugins/super-forms/uploads/php/files/b893debc65758638f481b6452d3086ed/85311116855.pdfIn PDF document text
    • http://sfalojistik.com/userfiles/file/jolejevazitusunomozoxenu.pdfIn PDF document text
    • https://fiscalonline.eu/app/webroot/files/userfiles/files/29760499628.pdfIn PDF document text
    • https://nvsrolko.org/ckfinder/userfiles/files/81931818216.pdfIn PDF document text
    • https://eltonltd.ru/sites/default/files/uploads/xaligubipixejexawefomasi.pdfIn PDF document text
    • http://akekaluck.com/ckfinder/userfiles/files/6200030026.pdfIn PDF document text
    • https://houstoncoinshow.org/FCKeditor/file/21086580675.pdfIn PDF document text
    • http://phunggia.biz/userfiles/file/86601823104.pdfIn PDF document text
    • http://cnsgawefgl.netsociality.com/upload/files/45321935434.pdfIn PDF document text
    • https://108pizza.pl/uploads/userfiles/files/favixoribenijuze.pdfIn PDF document text
    • http://fine-trading-knotwork.de/uploads/media/3247364771.pdfIn PDF document text
    • https://csp-pub.com/stockages/files/lenujesodup.pdfIn PDF document text
    • http://teen.plovdivweek.com/js/ckfinder/userfiles/files/vuwavegotonazawagekuvolud.pdfIn PDF document text
    • http://h-p-n.fr/catalogue_dynamique/file/nuzifavesosadotelafofumig.pdfIn PDF document text
    • http://sushiyaslo.com/uploads/files/63748039053.pdfIn PDF document text
    • http://ibshop.gr/uploads/_uploads/files/xexegomokop.pdfIn PDF document text
    • https://www.travelknowhowscotland.co.uk/assets/js/ckfinder/userfiles/files/lufojebirorinilasuzakab.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/1KS0DP0cxss/uplcv?utm_term=accounting+information+system+lecture+notes+pdfPDF link annotation
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In PDF document text
    • http://purl.org/dc/elements/1.1/In PDF document text
    • http://ns.adobe.com/pdf/1.3/In PDF document text
    • http://ns.adobe.com/xap/1.0/In PDF document text
    • http://ns.adobe.com/xap/1.0/mm/In PDF document text
    • http://ns.adobe.com/xap/1.0/rights/In PDF document text
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000b42e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB42E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000cc40.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCC40 16032 bytes
SHA-256: 0be6ca8a8ab86b0db7e5e8326e143db5c99bf02c0ee3f18a1fb6febdad00ccae
font_02_sfnt_off0000f549.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF549 11160 bytes
SHA-256: a5ab1aff556d47c1991ee5b06ce868a0bd687a4e059688a7ffb23f591eca766e