Malicious PDF — malware analysis report

Static analysis result for SHA-256 cded6c55226e6b24…

MALICIOUS

PDF

87.2 KB Created: 2021-09-05 10:11:25 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 55212110272c073495f63665fc18cd00 SHA-1: f046fef41aee41930665c1b47d949aada4493963 SHA-256: cded6c55226e6b24219019600308776ace81e167154f89f23726317481a8e0a3
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains numerous embedded URLs, many pointing to compromised WordPress sites, which likely serve as part of a link farm. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' indicates these links are designed for SEO manipulation and potentially to obscure malicious destinations. No scripts were extracted, but the structure suggests the PDF's primary purpose is to redirect users through these links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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://kvartira-zalog.ru/wp-content/plugins/super-forms/uploads/php/files/1ff6d3251c1c0c552977941a0ab1da59/bogowapesibapirexuwa.pdf In PDF document text
    • https://www.rath-catering.de/wp-content/plugins/formcraft/file-upload/server/content/files/160c90aa981cbe---71247435187.pdfIn PDF document text
    • https://luxartparquet.com/wp-content/plugins/super-forms/uploads/php/files/d34ed6226a5ee887010e0f7ad7433f12/zugujasezowiloxanowam.pdfIn PDF document text
    • http://jamoncup.es/wp-content/plugins/formcraft/file-upload/server/content/files/16091deadcac50---90226467827.pdfIn PDF document text
    • https://na-nule.ru/wp-content/plugins/super-forms/uploads/php/files/cf6st9429ivc08rjej6g1qkm81/gibewake.pdfIn PDF document text
    • http://savalis.ru/userfiles/file/relaxabo.pdfIn PDF document text
    • http://erfaspot.com/resimler/files/xodomabox.pdfIn PDF document text
    • http://www.barankayalar.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/1609788e352787---53006622692.pdfIn PDF document text
    • https://regalcabs.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160d29a35168cb---vukiw.pdfIn PDF document text
    • http://www.kissdocs.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1608fbe9c6fcb3---65630508196.pdfIn PDF document text
    • https://www.sahabatkeluargahomecare.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607dfb19998e5---38031105379.pdfIn PDF document text
    • https://www.goldenplanet.dk/wp-content/plugins/formcraft/file-upload/server/content/files/16126f67ba6f89---dodanozegiz.pdfIn PDF document text
    • http://uniradioweb.info/userfiles/files/22941132527.pdfIn PDF document text
    • https://www.sir.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160d5c965596cb---28357520567.pdfIn PDF document text
    • http://sisparts.pl/zdjecia/fck/file/44674037278.pdfIn PDF document text
    • http://studiobaldizzone.com/userfiles/files/19511764378.pdfIn PDF document text
    • https://fatheragneliti.com/wp-content/plugins/formcraft/file-upload/server/content/files/160855330958fe---xepusifopajinuzaga.pdfIn PDF document text
    • http://projectbudapest.hu/wp-content/plugins/formcraft/file-upload/server/content/files/16072ee85890e8---zerewojodaseniwagak.pdfIn PDF document text
    • http://clearspace-design.com/CKEdit/upload/files/zepuwamufuditujogiwuzik.pdfIn PDF document text
    • http://al-farh-iq.com/upload/userfiles/file/1224657332.pdfIn PDF document text
    • https://greenvalleykerala.com/ckfinder/userfiles/files/jolagapurewu.pdfIn PDF document text
    • https://alkhairi.co.uk/wp-content/plugins/super-forms/uploads/php/files/354c6186c55dade05ce8f24dab429116/2316692332.pdfIn PDF document text
    • http://benthanhsgfarm.com/images/uploads/files/91041803880.pdfIn PDF document text
    • https://bk.knu.ac.kr/ckfinder/userfiles/files/37173383308.pdfIn PDF document text
    • http://itnetworkconsultingsf.com/helpdesk/app/webroot/img/userfiles/files/36514330628.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/A3Ryygt5BCM/uplcv?utm_term=zero+condicional+ejercicios+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_off0000ec01.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEC01 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00010413.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10413 19904 bytes
SHA-256: bbedd10a66b2d5f5b44d26c945419f6956d137e89e22af70714d1ed081c98e56
font_02_sfnt_off000136c1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x136C1 10608 bytes
SHA-256: 9c6805892916614ffb848f0c0f398317f8b37e34c1411320ec598591eb496112