Malicious PDF — malware analysis report

Static analysis result for SHA-256 3c157a24fcd3996d…

MALICIOUS

PDF

80.9 KB Created: 2021-09-13 00:58:18 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: c8f0a7c7015ec1a348fd144cb771ec59 SHA-1: 5837c247be6ee86241995b820932d54ab1a5443e SHA-256: 3c157a24fcd3996df7b53b4bf55b3643e3721cd5729689707ef2159589dd8ad0
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

This PDF file was flagged as malicious by ClamAV and an ML classifier. It contains a large number of embedded URLs, many of which point to compromised WordPress sites or disposable hosting, suggesting a link farm designed to redirect users to malicious content. The presence of multiple PDF_URI and PDF_SEO_DISPOSABLE_LINK_FARM heuristics further supports this attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9949

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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.
  • 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://headrepublic.pl/images/files/45676461205.pdf In PDF document text
    • http://viaterrestre.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1613a7b5736eca---risisosanawukaji.pdfIn PDF document text
    • https://detectagsafety.com/ckfinder/userfiles/files/tuworudi.pdfIn PDF document text
    • https://sunnyvale.com/wysiwygfiles/file/wulozububalosoki.pdfIn PDF document text
    • http://jjburgerut.com/uploads/files/fogavu.pdfIn PDF document text
    • https://yantrasearch.com/ckfinder/userfiles/files/mozipatufogegipedulegawu.pdfIn PDF document text
    • https://medius.sk/userfiles/file/16946877661.pdfIn PDF document text
    • https://jin-ji.com/upload/files/86671011658.pdfIn PDF document text
    • https://www.bouwenaaneensterkwerkgeversmerk.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1613b88b3cc2eb---50140564750.pdfIn PDF document text
    • https://areopag.ru/sites/default/files/uploads/firuniwelusema.pdfIn PDF document text
    • https://dbjadow.pl/attachments/file/situlisokulixe.pdfIn PDF document text
    • http://www.florentmaussion.net/userfiles/File/45414936201.pdfIn PDF document text
    • http://chocolatycakes.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613495fcbfdaa---rimikejupidelekowezu.pdfIn PDF document text
    • http://orvositudasbazis.eu/images/upload/file/3464688695.pdfIn PDF document text
    • http://elijasprojekts.lv/files/file/67185999400.pdfIn PDF document text
    • http://sacoorhealth.pt/site/upload/file/44617959024.pdfIn PDF document text
    • https://novsport.com/content/File/wamax.pdfIn PDF document text
    • http://www.pataniforum.com/admin/jquery/ckfinder/userfiles/files/57798235992.pdfIn PDF document text
    • http://studiotecniconuti.it/userfiles/files/6511640683.pdfIn PDF document text
    • http://kietminhrivet.com/upload/files/labetemanizete.pdfIn PDF document text
    • http://gryfarmerskie.pl/pliki_wyswig/files/11565226400.pdfIn PDF document text
    • https://suemsas.com/wp-content/plugins/super-forms/uploads/php/files/ikg1ro472j25cvv1rsk2su1612/55747758576.pdfIn PDF document text
    • http://kibunajcc.com/ckfinder/userfiles/files/69020576048.pdfIn PDF document text
    • http://citra.cl/userfiles/file/wanelakazap.pdfIn PDF document text
    • https://enville.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612eb573e3343---baketutapibaxalizineteki.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/YTWXjIUwRh0/uplcv?utm_term=english+file+intermediate+fourth+edition+key+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_off0000d131.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD131 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000e943.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE943 19412 bytes
SHA-256: e67eb6d6f241db25df6048b93353d38ad01a07686ba2ea6fd9780dc52e3537e6
font_02_sfnt_off00011c2c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11C2C 11232 bytes
SHA-256: be0d72e5d2b5a16c345a16c8e6f8f6e502e4a4008d25a0514a5155e3faa4bbe5