Malicious PDF — malware analysis report

Static analysis result for SHA-256 4b31a8e4db6db339…

MALICIOUS

PDF

75.6 KB Created: 2021-09-07 18:35:38 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: 591521e918c91bbef9ba1e5c1dda047e SHA-1: f748ffb5181880a9b60405ff0745852a9bfbf38a SHA-256: 4b31a8e4db6db3398ae2174b916b959d848a8bdbf6c280f897350ef317c6522b
156 Risk Score

Malware Insights

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

The PDF contains a large number of links, many of which point to compromised CMS upload directories or disposable hosting, indicating a link farm designed for SEO manipulation or to distribute malicious content. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or malware distribution through these links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9976

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://ranaghatpchsschool.org/userfiles/file/14001420087.pdf In PDF document text
    • http://rheumatology.instituteupload/content/file/64888084849.pdfIn PDF document text
    • https://readxyz.org/wp-content/plugins/super-forms/uploads/php/files/3a25d1ad9df5d9d0197ac53135161b55/wopuk.pdfIn PDF document text
    • https://amirep.com/wp-content/plugins/super-forms/uploads/php/files/cc193aad68428cb2f0fbedcc431e15e4/bizikabipulewopaxadum.pdfIn PDF document text
    • http://www.magicapro.it/wp-content/plugins/formcraft/file-upload/server/content/files/16075958033e36---85313842456.pdfIn PDF document text
    • http://vom-ragnaroek.de/uploads/file/94465553069.pdfIn PDF document text
    • http://vaness-sens.fr/ckfinder/userfiles/files/75365453482.pdfIn PDF document text
    • https://xigmatek.com/upload/files/sanojozewitofal.pdfIn PDF document text
    • https://presstone.hu/userfiles/file/xijipomadekes.pdfIn PDF document text
    • https://tonitomov.com/picture/file/wasojumilofawaxagetenup.pdfIn PDF document text
    • https://lifesmart.ro/ckfinder/userfiles/files/piniwetof.pdfIn PDF document text
    • http://mmdplus.com/userfiles/files/20210709_122613.pdfIn PDF document text
    • https://provisionsinternational.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609905ecc526f---30681764462.pdfIn PDF document text
    • https://www.medicalart.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/1606c78efd9c18---15726346753.pdfIn PDF document text
    • http://shopsuathientu.com/uploads/userfiles/file/75436998726.pdfIn PDF document text
    • http://agataklimowska.pl/userfiles/file/59757695358.pdfIn PDF document text
    • https://mirrorlink.com/public/files/files/3808128391.pdfIn PDF document text
    • http://www.ags-sib.ru/ckfinder/userfiles/files/35755791186.pdfIn PDF document text
    • http://www.everhouse.lt/wp-content/plugins/formcraft/file-upload/server/content/files/16082fdffa672d---letuzen.pdfIn PDF document text
    • http://arvikabc.com/images/uploadedimages/file/wawaresugaxavu.pdfIn PDF document text
    • https://www.xtremefitness.com.au/application/third_party/ckfinder/userfiles/files/tuwefos.pdfIn PDF document text
    • https://wurstfargo.com/wp-content/plugins/super-forms/uploads/php/files/d031f745b4ae3e90743fa74cc24feaf1/56061476606.pdfIn PDF document text
    • http://daonshop.com/files/fckeditor/file/23667858380.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/FevRqgeaUVY/uplcv?utm_term=role+of+ncert+in+teacher+education+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_off0000c63a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC63A 10692 bytes
SHA-256: 2f5c23c504578b880ffaf08d24f6aa277f981568167f4b4b2635c3d384e716cb
font_01_sfnt_off0000dea4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDEA4 16268 bytes
SHA-256: e121305f710e6c5b1334710b3ba09e35ccfd99685a3a3c3c4dbe0c68b5592f92
font_02_sfnt_off0001088b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1088B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1