Malicious PDF — malware analysis report

Static analysis result for SHA-256 b9940482eb7c8a59…

MALICIOUS

PDF

104.0 KB Created: 2021-08-14 09:35:59 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: b60db44bb6e0c6b89c825a8ad2b22468 SHA-1: f8eb4e67eb4622fb71fc9f67c1db93837d40fc93 SHA-256: b9940482eb7c8a59614a349129ebd04c831672f28d691c4ee207d00bb279005b
156 Risk Score

Malware Insights

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

This PDF file was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. It contains numerous embedded URLs, many of which point to compromised WordPress sites or disposable hosting, suggesting a link farm designed to redirect users to malicious content. The document body is heavily obfuscated and appears to be non-readable content generated by wkhtmltopdf, providing no direct user-facing lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9979

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://envomask.com/wp-content/plugins/super-forms/uploads/php/files/056e220e3a249ecab15d2219ed766170/ripaw.pdf In PDF document text
    • http://snap-drone.com/userfiles/file/90840086367.pdfIn PDF document text
    • http://www.appsolutely.sg/wp-content/plugins/formcraft/file-upload/server/content/files/160ab6ed3c363e---10074188021.pdfIn PDF document text
    • http://terminsk.by/pics/files/72314505490.pdfIn PDF document text
    • https://voyagerf.ru/wp-content/plugins/super-forms/uploads/php/files/a04ae5de01fa98f98830f7c73186013b/lapegefomifazomud.pdfIn PDF document text
    • https://thefencedocumentary.com/adminfiles/file/27992009889.pdfIn PDF document text
    • https://djhelaly.com/wp-content/plugins/super-forms/uploads/php/files/db09a9eafac49ca7f5c260521db40053/644419660.pdfIn PDF document text
    • https://sellos-mecanicos.com/wp-content/plugins/super-forms/uploads/php/files/3beae1b81ca08a3cd2036b59a414d59a/gavawu.pdfIn PDF document text
    • http://hwayinn.com/image/files/20210724_031846.pdfIn PDF document text
    • https://www.jahnigterbraak.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1606d692f23703---48361599311.pdfIn PDF document text
    • http://cmtdental.com/upload/ckimg/files/gipotofoxutiguxitefo.pdfIn PDF document text
    • http://a-range.ru/wp-content/plugins/formcraft/file-upload/server/content/files/160d48d6056e9d---77209884150.pdfIn PDF document text
    • http://diencongnghiepvohoang.com/uploads/files/78530894313.pdfIn PDF document text
    • http://ngpsusa.com/wp-content/plugins/super-forms/uploads/php/files/fvb90j8b70ce6ihpnp77h8pc36/duralogaluwav.pdfIn PDF document text
    • https://seroinstitute.com/wp-content/plugins/super-forms/uploads/php/files/04b64a4e91b839a3a77935f55e9d29dd/daranaboxoto.pdfIn PDF document text
    • http://mobilenmr.com/files/files/97646221932.pdfIn PDF document text
    • https://g3az.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b954e33af31---wobimugupuperiga.pdfIn PDF document text
    • http://fsoa.cn/userfiles/file/17018645526.pdfIn PDF document text
    • https://emprenderem.cl/files/jofup.pdfIn PDF document text
    • http://myphammonly.com/luutru/files/78746402887.pdfIn PDF document text
    • http://northphoenixmustangs66.com/clients/4/4b/4b49b54eec06ebba3741256e9f3e6f2b/File/54925217553.pdfIn PDF document text
    • https://wamsconference.com/wp-content/plugins/super-forms/uploads/php/files/4da39d862f2a755c9e85fdac762078d1/difim.pdfIn PDF document text
    • https://chicagoportablexray.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c9756863abc---26847541899.pdfIn PDF document text
    • https://medosojewellery.com/userfiles/files/54367902601.pdfIn PDF document text
    • http://jeugdopdewetenschapsagenda.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160c485b223079---30878865810.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/6naE_Nh8_CY/uplcv?utm_term=akademia+pana+kleksa+ca%C5%82a+lektura+audiobookPDF 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_off00012da5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12DA5 11060 bytes
SHA-256: f8362befe9743ec89b46d1baf5d1290cb86e01bd7c180ec0f3b31ed9a0b205a8
font_01_sfnt_off0001472d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1472D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00015f3f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x15F3F 19012 bytes
SHA-256: e3ce45232a2f32e15c6dbb923234d3cee49e66143b5b2b4c566fe33e84f6bd72