Malicious PDF — malware analysis report

Static analysis result for SHA-256 4f5a52479838c1f6…

MALICIOUS

PDF

84.5 KB Created: 2021-08-09 20:42:22 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 7fb502d52538aa7bada9c816433edfa7 SHA-1: b0a3ea2c44bc5e73f111c046d8ee3096a27625a8 SHA-256: 4f5a52479838c1f66e11b2ffc7d298c08212f7eb15b8e17b2d258e019946abd6
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous links pointing to compromised WordPress sites and disposable hosting, indicating it functions as a link farm. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or malware distribution. Although no scripts were explicitly extracted, the PDF structure and link farm behavior are indicative of malicious activity.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9980

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://indel.sk/userfiles/file/14356958016.pdf In PDF document text
    • http://www.fullmooneye.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a28dfbc82a8---wikamurizis.pdfIn PDF document text
    • http://smartmedicaleg.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609416740e5bc---44570888331.pdfIn PDF document text
    • https://proff-doors.ru/wp-content/plugins/super-forms/uploads/php/files/55bdbcc8ae3edd657eb813aba35d6571/pusomozapajokawa.pdfIn PDF document text
    • https://www.advids.co/wp-content/plugins/formcraft/file-upload/server/content/files/1608ae34ced470---26401783725.pdfIn PDF document text
    • http://www.movingintofreedom.com/wp-content/plugins/formcraft/file-upload/server/content/files/160aa65216ce25---kazak.pdfIn PDF document text
    • https://gpuhub.net/wp-content/plugins/super-forms/uploads/php/files/lp19s8cs9l1397s8ifb1nmhaoh/99552067396.pdfIn PDF document text
    • https://studio45.live/wp-content/plugins/super-forms/uploads/php/files/dtbq879rnur63g9f4su5rl0c3k/1304197890.pdfIn PDF document text
    • http://tutaylamhet.com/storage/ckfinder/files/6429345571.pdfIn PDF document text
    • https://cspdental.com/wp-content/plugins/super-forms/uploads/php/files/9197866a006d1a6a96694c6f87eb87a2/1536846845.pdfIn PDF document text
    • https://www.scanworld.se/wp-content/plugins/formcraft/file-upload/server/content/files/1607d9f85b95d2---68073165502.pdfIn PDF document text
    • http://www.expertnutritionadvisor.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608042075095d---zovetu.pdfIn PDF document text
    • http://chagatea.ru/wp-content/plugins/super-forms/uploads/php/files/830d57397f0aee8d7ec14583aada8d71/rovibepojez.pdfIn PDF document text
    • https://mehreganimaging.ir/images/upload/files/37298974769.pdfIn PDF document text
    • http://kukubara.com/zdjecia/file/63490236464.pdfIn PDF document text
    • http://www.annaleehuber.com/content_files/file/jenagizuzudovarab.pdfIn PDF document text
    • https://vietrocknet.org/app/webroot/img/files/fiwakomefu.pdfIn PDF document text
    • https://www.marvistasales.com/wp-content/plugins/super-forms/uploads/php/files/1a3908b3c61c660078a9a86f3ec886b9/lafuvafarixabudugowogovi.pdfIn PDF document text
    • http://hitechdentalhouston.com/uploads/files/19971633487.pdfIn PDF document text
    • http://krindustria.com.br/site/wp-content/plugins/formcraft/file-upload/server/content/files/16081a9412e4f9---lefejimewizuwewupume.pdfIn PDF document text
    • http://www.peretprod.ro/content-images/file/wejavigadolumexaf.pdfIn PDF document text
    • http://www.inhd.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160b65ee903bb8---bizokej.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/LPIa9PGmDLg/uplcv?utm_term=paediatric+advanced+life+support+videoPDF 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_off0000e5df.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE5DF 10780 bytes
SHA-256: 73441b8dbf7479df21fab832fb4c61d7628d64e7d16ac860a447bcde90991074
font_01_sfnt_off0000feca.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFECA 17264 bytes
SHA-256: 3331fdd8460b0f1dbd3f7c0339305ce78a7a4b5e6d6bb40a44d3e37d499441c3
font_02_sfnt_off00012c40.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12C40 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1