Malicious PDF — malware analysis report

Static analysis result for SHA-256 82a8ab022eb259da…

MALICIOUS

PDF

75.2 KB Created: 2021-09-19 15:34:57 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: b58dfb64ec2613c7daf59386e40af4c1 SHA-1: 145a6cf052c6e1880f70ce756e937f334179584d SHA-256: 82a8ab022eb259dab4d1944da0376f1911005ca4a88663a4f71c3b26edb54841
156 Risk Score

Malware Insights

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

This PDF file was flagged by multiple heuristics as malicious, including a critical ClamAV detection and an ML classifier indicating a high probability of maliciousness. It functions as a link farm, containing numerous URLs pointing to various domains, many of which are hosted on disposable or compromised CMS upload storage. The primary purpose appears to be directing users to external sites, likely for phishing or to download further malicious content.

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 http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614093126560d---kuxexutibaxudubogogazizos.pdf In PDF document text
    • http://fskyok.com/uploadfile/files/15988040468.pdfIn PDF document text
    • http://ahxxzx.com/userfiles/202109/file/jawera.pdfIn PDF document text
    • http://cdkuysuujk.handysociality.com/upload/files/folotup.pdfIn PDF document text
    • http://srs-budapest.hu/uploads/files/pedezides.pdfIn PDF document text
    • http://downtowncincyhotels.com/core_degree/admin/images/cms_imagesfiles/sojavumiderizod.pdfIn PDF document text
    • http://www.hcibatiment.fr/wp-content/plugins/formcraft/file-upload/server/content/files/16134a81d79f5a---32208073491.pdfIn PDF document text
    • http://www.unidacardoso.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1613fc5cd99bd0---35457875910.pdfIn PDF document text
    • http://akkoryazilim.com/userfiles/file/3204086027.pdfIn PDF document text
    • http://www.putnamtaxi.net/wp-content/plugins/formcraft/file-upload/server/content/files/1613a2366d6d3c---55375072146.pdfIn PDF document text
    • http://totaleclipsenv.com/wp-content/plugins/formcraft/file-upload/server/content/files/161343e4653798---57482152621.pdfIn PDF document text
    • http://vkts.se/userfiles/file/3273706147.pdfIn PDF document text
    • https://collinite.pl/userfiles/file/4393313449.pdfIn PDF document text
    • http://er-trans.com/img/produkty/files/tumobadabamizazefenizitel.pdfIn PDF document text
    • https://namastehealth.in/wp-content/plugins/super-forms/uploads/php/files/ltdfvnlem6ofieggumkhl27lp9/kovasevexukadimuz.pdfIn PDF document text
    • http://rexant.by/upload/editor/files/24787560016.pdfIn PDF document text
    • http://rlangkhan.com/upload/userfiles/files/77080854785.pdfIn PDF document text
    • http://telecycling.org/files/file/33765663367.pdfIn PDF document text
    • http://tinhdauvietnam.vn/upload/files/63605832136.pdfIn PDF document text
    • https://norservis.com/files/files/fikibofak.pdfIn PDF document text
    • http://makaroma.fr/upload/file/25531063569.pdfIn PDF document text
    • http://klasykarozrywki.pl/public/images/fck/file/16687085945.pdfIn PDF document text
    • http://autoscuolemontagna.it/userfiles/files/12157586848.pdfIn PDF document text
    • https://cr2tek.com/userfiles/Proj_Name/files/28609875376.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/ngfLrbzwjls/uplcv?utm_term=top+non+android+smartphonesPDF 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_off0000c435.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC435 10572 bytes
SHA-256: a536c54a38ba9d50188cedbd02c2fc962c112f52df3f01814ee27b468f6f8e0b
font_01_sfnt_off0000dc1c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDC1C 16584 bytes
SHA-256: bf061360ad53773d210072f4ca1e4e1b51bacb5d3ec92dea07465bd0560b1cf5
font_02_sfnt_off000106ec.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x106EC 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1