Malicious PDF — malware analysis report

Static analysis result for SHA-256 fdb71e6d27827b5b…

MALICIOUS

PDF

77.3 KB Created: 2021-09-13 13:54:27 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: c05e2ad8f0db76aa761838036cde7c78 SHA-1: 37fd4a578f1b7aede4ba9b7a539294a2c1815699 SHA-256: fdb71e6d27827b5b83b00b7add998df61a815e42b558dc9603d82b9a312de87c
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as malicious by ClamAV and an ML classifier, and exhibits characteristics of a link farm. Multiple heuristics indicate the PDF contains numerous external links, many pointing to compromised WordPress upload directories, suggesting an attempt to redirect users to malicious sites. The presence of embedded URLs and the overall structure point towards a phishing or malware distribution scheme.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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 https://coretry.ru/uplcv?utm_term=minecraft+java+edition+for+android+for+free PDF link annotation
    • https://carthink.org/wp-content/plugins/formcraft/file-upload/server/content/files/16131dc1fc4183---80838039155.pdfIn PDF document text
    • http://www.stratcareerservices.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613e87f76c5e8---29253196194.pdfIn PDF document text
    • https://matricula.netlandschool.cl/files/raxufukijazezixinixodid.pdfIn PDF document text
    • http://huefpdf.org/upload/file/71074857190.pdfIn PDF document text
    • http://www.ambatownship.com/ckfinder/userfiles/files/8741849366.pdfIn PDF document text
    • https://lotteppta.com/beta/assets/file/xukelanerijezobod.pdfIn PDF document text
    • http://aokisuper.com/ckfinder/userfiles/files/liretusajaragixumobewoden.pdfIn PDF document text
    • https://stpm-sa.com/userfiles/file/wawepoligazuxor.pdfIn PDF document text
    • https://oneremote.ru/wp-content/plugins/super-forms/uploads/php/files/e5efb3531f9249c1b03d9d5b6df35e8b/getijujugenod.pdfIn PDF document text
    • http://modernplating.com/userfiles/file/15951275242.pdfIn PDF document text
    • http://vaness-sens.fr/ckfinder/userfiles/files/50444625930.pdfIn PDF document text
    • https://shoppingplanet.ro/ckfinder/userfiles/files/79201114174.pdfIn PDF document text
    • http://becucci.it/userfiles/files/54967292148.pdfIn PDF document text
    • http://stefanourso.com/public/userfiles/file/vulokibarunokoxelorowo.pdfIn PDF document text
    • http://escolacaritas.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613e7aafed84b---mikubafilijisodimubik.pdfIn PDF document text
    • https://movingalpsfoundation.ch/userfiles/file/metusupeligedij.pdfIn PDF document text
    • http://xn--80adpfaaeictf0c6c7i.xn--p1ai/public/file/82086475266.pdfIn PDF document text
    • http://mosvag.ru/img/lib/file/59429766287.pdfIn PDF document text
    • https://alfa-clining.ru/wp-content/plugins/super-forms/uploads/php/files/8548299572218e828855d9dc4e342812/sutiler.pdfIn PDF document text
    • https://fontan-montag.ru/img/upload/76731917918.pdfIn PDF document text
    • http://galettedesrois.eu/userfiles/file/kafen.pdfIn PDF document text
    • http://garantc.ru/userfiles/file/sezebijubogudujexeniko.pdfIn PDF document text
    • https://yourtuscanyguide.com/wp-content/plugins/super-forms/uploads/php/files/ufpd4g0uvbs20gg6fftid8nu45/48325492858.pdfIn PDF document text
    • https://anitt.in/ckfinder/userfiles/files/wapevojuve.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_off0000cbbc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCBBC 10444 bytes
SHA-256: 1d77cc7d8d46c918c610b5012ec8f8956ee26c9289808ba7af190d3cd609e4bc
font_01_sfnt_off0000e38a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE38A 16788 bytes
SHA-256: 1c041f5254f766fab9936fdf8121a2b4e5be600799166c76ba0ab1c98133fa8e
font_02_sfnt_off00010eee.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10EEE 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1