Malicious PDF — malware analysis report

Static analysis result for SHA-256 643d37dd1f1a7c8e…

MALICIOUS

PDF

77.1 KB Created: 2021-09-14 18:11:05 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: acd0089dac7fa2b8fdb4d8c4921dc2c1 SHA-1: 478cf9febd9acfb93d55d8ffdf59bf2ccefa14f2 SHA-256: 643d37dd1f1a7c8ef59d7afc9f46350cfcb8895500081a7129e9230d3b70b049
134 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript and numerous external URIs, many of which are part of a link farm hosted on disposable domains. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. The embedded JavaScript is likely used to facilitate redirection or exploit vulnerabilities.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9840

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://huntic.ru/uplcv?utm_term=cheats+war+robots PDF link annotation
    • http://gayaarchi.com/userfiles/file/20210905230011.pdfIn PDF document text
    • http://allamericannursing.com/userfiles/file/59435196588.pdfIn PDF document text
    • http://surausa.com/uploads/files/xosizamosofewoji.pdfIn PDF document text
    • http://chekeeh.ir/basefile/chekeehir/files/vakurivimadupavo.pdfIn PDF document text
    • https://schachverein-marchhoefe.ch/fcsr/news/upload/file/37932375676.pdfIn PDF document text
    • http://nhatngungoisaoxanh.com/upload/files/45203409287.pdfIn PDF document text
    • https://schreinerheusi.de/wp-content/plugins/formcraft/file-upload/server/content/files/1613a85ea11e2f---8922921143.pdfIn PDF document text
    • http://xn--djr00fsyfv0o5qgy9u.net/filespath/files/20210912135725.pdfIn PDF document text
    • https://ladachess.ru/userfiles/file/55635736189.pdfIn PDF document text
    • http://www.sictombbi.fr/ckfinder/userfiles/files/mavifun.pdfIn PDF document text
    • http://madiran-cruduparadis.fr/ckfinder/userfiles/files/kumizoni.pdfIn PDF document text
    • https://limsurdua.com/contents/files/bobovuwogisitaravog.pdfIn PDF document text
    • https://wilocom.ro/ckfinder/userfiles/files/88512773979.pdfIn PDF document text
    • https://bamfieldrental.com/userfiles/file/89361031225.pdfIn PDF document text
    • http://aviapartner.biz/js/ckfinder/userfiles/files/50186197222.pdfIn PDF document text
    • http://lutechmed.com/Images_upload/files/bifanikotudatefiw.pdfIn PDF document text
    • http://xn--80aer5aza.xn--c1acndkmcarx.xn--p1ai/ckfinder/userfiles/files/89909080563.pdfIn PDF document text
    • http://graficaeformazione.it/userfiles/file/buzebexowaxozisofametun.pdfIn PDF document text
    • http://koszyczarek.pl/userfiles/file/gagizusodamukevuverogate.pdfIn PDF document text
    • http://balaton.varosom.hu/userfiles/files/23252527988.pdfIn PDF document text
    • https://weldingportal.it/userfiles/file/3670484805.pdfIn PDF document text
    • http://dakov.hu/_user/file/gopulegom.pdfIn PDF document text
    • http://lnv-cnc.gr/userfiles/file/9453332243.pdfIn PDF document text
    • http://nebovsem.ru/app/webroot/files/files/tazokowovifodujep.pdfIn PDF document text
    • https://iskoruma.com/upload/ckfinder/files/lugerewesebam.pdfIn PDF document text
    • https://solarconsulting.org/wp-content/plugins/super-forms/uploads/php/files/8c0ab2cd09a335309e3b377035c1abd5/gadilalixedufu.pdfIn PDF document text
    • 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_off0000cc06.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCC06 16960 bytes
SHA-256: 5a5db48d25af92754abdd97b05f0bd04d7312d440e22cae7ba52a43e793313ca
font_01_sfnt_off0000f7e1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF7E1 10220 bytes
SHA-256: 2e85bb2a4dc801729f78d9e168bdd94ef58f416f84deb3b912677d86a145a07c
font_02_sfnt_off00010f16.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10F16 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1