Malicious PDF — malware analysis report

Static analysis result for SHA-256 990cd492839c5d87…

MALICIOUS

PDF

83.1 KB Created: 2021-09-07 17:10:46 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 7841c6b97427a62a74fcd32a9ffbf927 SHA-1: 940837a0c7400f6b4c4128a92968a1b1598bb79d SHA-256: 990cd492839c5d875dfa26d6a2da74d1d5f8d7cb65c1755d9ad3b86fc2378681
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript, which is a common technique for executing malicious code within documents. Several heuristics indicate the PDF is part of a link farm, pointing to compromised WordPress sites and potentially disposable hosting, suggesting an attempt to distribute malicious content or phish users. The ML classifier and ClamAV detection strongly indicate malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9955

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • 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 http://plenar.hr/wp-content/plugins/formcraft/file-upload/server/content/files/160855af10cec5---xutenazixusoxiserozuvam.pdf In PDF document text
    • https://kheops-so.fr/ckfinder/userfiles/files/jatotetoparowupejof.pdfIn PDF document text
    • http://accomplishtheimpossible.com/userfiles_ati/file/17308936072.pdfIn PDF document text
    • https://baodinhsolar.com/wp-content/plugins/super-forms/uploads/php/files/2vsgpqd0pq262lh0dmrvd6eq76/78307294610.pdfIn PDF document text
    • http://capitaloffice.pl/fotki/file/matuk.pdfIn PDF document text
    • https://bikinibody.be/wp-content/plugins/super-forms/uploads/php/files/np8dm89lmb4v4lamlid916c4pr/24897111186.pdfIn PDF document text
    • http://industriefotografie.ch/userfiles/files/80408207504.pdfIn PDF document text
    • https://togeltop.net/contents/files/pegaget.pdfIn PDF document text
    • http://jmlukanich.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/60238797704.pdfIn PDF document text
    • http://cosonhuath.com/hinhanh_fckeditor/file/niwutekakipa.pdfIn PDF document text
    • http://biswasi.com/userfiles/files/14605413989.pdfIn PDF document text
    • https://esteticarcare.com/wp-content/plugins/super-forms/uploads/php/files/89041738405749e84ed4ba7d3642eb9c/62570408669.pdfIn PDF document text
    • https://sukaunited4d.vip/contents/files/41068751366.pdfIn PDF document text
    • http://makingthegradetexas.com/clients/d/d4/d4716c73f098ea79da165a2194b6736a/File/xowisodapidewiwemo.pdfIn PDF document text
    • http://hydrem.ru/images/file/xemajole.pdfIn PDF document text
    • http://guilfordvikingsclassof81.com/clients/4/47/479b0a304b4cdce99dfe3eda73a59016/File/58708956164.pdfIn PDF document text
    • https://ustunbilgisayar.com/userfiles/files/7277306051.pdfIn PDF document text
    • http://nassagroup.org/app/webroot/js/ckfinder/userfiles/files/javumibipupa.pdfIn PDF document text
    • http://makaeximworld.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606c7dd80a617---27956470677.pdfIn PDF document text
    • http://accessiblevehicleservices.com/userfiles/file/50680113673.pdfIn PDF document text
    • http://rethabise.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/16093bd4130668---xanulofeju.pdfIn PDF document text
    • http://vyveva.eu/UserFiles/File/16193384452.pdfIn PDF document text
    • http://audiomaster.se/wp-content/plugins/formcraft/file-upload/server/content/files/1610956fb9b917---47985620783.pdfIn PDF document text
    • http://www.vivelamusica.es/wp-content/plugins/formcraft/file-upload/server/content/files/16071c36a50635---99200503419.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/ngfLrbzwjls/uplcv?utm_term=seventh+chords+worksheet+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_off0000dcf7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDCF7 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f50e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF50E 10736 bytes
SHA-256: 10b31e23d3d207acfa932b5e02902aa25a58468252b1812922a334c221d2a8ed
font_02_sfnt_off00010db7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10DB7 19164 bytes
SHA-256: f9dee8e30af9c723292efa4e6b4b22dbdf4ad29ea73dc6d3ef714409b7527869