Malicious PDF — malware analysis report

Static analysis result for SHA-256 3fb9b53a1e28fc33…

MALICIOUS

PDF

72.5 KB Created: 2021-10-02 14:28:10 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: f45feb4f91c06ce9d2a99d853d418724 SHA-1: de240af7fca7c8bad0df311b863a4feb7e9a3b65 SHA-256: 3fb9b53a1e28fc336704fc82a88b05863e07f5e4ef8caac228621549f24eea73
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file is identified as malicious by ML classifiers and ClamAV, indicating it's a phishing or trojan PDF. It functions as a link farm, with numerous embedded URLs pointing to compromised WordPress sites and disposable hosting, likely to obscure the final malicious destination. The presence of external URIs and link farm heuristics strongly suggests an attempt to lure users to external sites, potentially for credential harvesting or malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9908

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://asaptransfers.co.uk/wp-content/plugins/super-forms/uploads/php/files/f60d6290b8771d817c66b3d93cb6516f/lugidavonijake.pdf In PDF document text
    • https://kluchar.net/klucharnet/images/file/zobuzozuj.pdfIn PDF document text
    • http://watch62.ru/files/files/jikadewurivikuveza.pdfIn PDF document text
    • https://emergent-partners.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613fc1cc9ff98---89093371459.pdfIn PDF document text
    • https://cargoservice.pl/cargoservice/userfiles/file/kegejiroveniwipujabuj.pdfIn PDF document text
    • https://xistenze.nagydavid.com/files/files/siraluxovenufisixaw.pdfIn PDF document text
    • http://www.moyekolodin.com/files/figipipazimofugovosutu.pdfIn PDF document text
    • https://emailing-online.fr/uploads/userfiles/file/jilujew.pdfIn PDF document text
    • https://wct.goldcrownresort.com/magazine_files/files/vagokefumodaxer.pdfIn PDF document text
    • https://www.xcelsus.de/wp-content/plugins/formcraft/file-upload/server/content/files/16139bdf71977f---pofularul.pdfIn PDF document text
    • https://www.osteopathe-montpellier-sud.fr/ckfinder/userfiles/files/21727627382.pdfIn PDF document text
    • http://enslev-anlaegsservice.dk/userfiles/file/16222171427.pdfIn PDF document text
    • http://321eastern-thailand.com/userfiles/files/doxugiliwabi.pdfIn PDF document text
    • http://indago-rovigo.it/userfiles/files/55620608420.pdfIn PDF document text
    • https://aokman-drive.com/d/files/gizutifuxefifasotuta.pdfIn PDF document text
    • https://tahitotfaluovodak.hu/ckfinder/userfiles/files/bivevamisowewi.pdfIn PDF document text
    • http://pavcargo.ru/wp-content/plugins/super-forms/uploads/php/files/f8a7acb15037c96f0c63f4c724198cc2/14083472177.pdfIn PDF document text
    • https://edex.co/userfiles/files/44340716226.pdfIn PDF document text
    • https://maftplayer.net/calisma2/files/uploads/17576594534.pdfIn PDF document text
    • http://workontext.ru/media/file/49284500622.pdfIn PDF document text
    • http://socialbomjesus.org.br/wp-content/plugins/formcraft/file-upload/server/content/files/1613f22485874f---kezubavamafonogalan.pdfIn PDF document text
    • http://hladonural.ru/upload_picture/4719968560.pdfIn PDF document text
    • http://himalayakebab.irafbrothers.com/shipinc/userfiles/files/najokaninebad.pdfIn PDF document text
    • http://copy2d.com/ftp/image/file/bipinipozonalisikufixaj.pdfIn PDF document text
    • http://henzefashion.com/userfiles/file/20978510460.pdfIn PDF document text
    • https://www.histoiresdegroupes.com/wp-content/plugins/formcraft/file-upload/server/content/files/161557358d2586---84862552439.pdfIn PDF document text
    • http://www.css-jp.com/upfile/files/2021/09/30/wekekekinexuxanuzumafexuk.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/3CAf4wW3hvY/uplcv?utm_term=electric+and+hybrid+vehicles+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_off0000b8c6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB8C6 16388 bytes
SHA-256: 0868ecb654d7f84b0c9a30145245a3ba00081b1c8f85d700a3303b540e2ce60e
font_01_sfnt_off0000e2f4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE2F4 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000fb0b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFB0B 10900 bytes
SHA-256: a25e2a8a9e89696c3af31c399be3aa7e23b862574dc65d049dc2f3219ac87ffd