Malicious PDF — malware analysis report

Static analysis result for SHA-256 535ac6eb7a64eb56…

MALICIOUS

PDF

79.5 KB Created: 2021-09-20 00:25:30 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: 898c8d13c2f65ddde59e6b32fe1e778c SHA-1: 1df9789f71aafc30ba4868e71b18dcfb9028e84c SHA-256: 535ac6eb7a64eb56b0095a6626f9125f911895ebdbb161ab0376126e0d6884ff
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF contains a link farm with numerous URLs, many pointing to compromised or disposable hosting, suggesting a phishing or malware distribution attempt. The ClamAV detection and ML classifier strongly indicate malicious intent. While no scripts were extracted, the structure and embedded URLs are indicative of a phishing lure designed to redirect users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9949

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.medic-pneumolog.ro/fisiere/file/27667471958.pdf In PDF document text
    • http://cgt-fo-csc.fr/wp-content/plugins/formcraft/file-upload/server/content/files/1613c78de6c6c3---37685757017.pdfIn PDF document text
    • http://lev-steklo.ru/userfiles/file/fikifam.pdfIn PDF document text
    • https://watfordfairtrade.org/app/webroot/img/files/67518699486.pdfIn PDF document text
    • http://ranjitabiswas.com/userfiles/files/14839462432.pdfIn PDF document text
    • http://kartinatv.org/uploads/files/48466487795.pdfIn PDF document text
    • http://mtsskzy.com/userfiles/file/59357275894.pdfIn PDF document text
    • http://myphamlulanjina.com/upload/files/92288956066.pdfIn PDF document text
    • http://fu-xin.tw/uploads/files/202109172151286395.pdfIn PDF document text
    • http://cungcapluonech.com/upload/files/26303984750.pdfIn PDF document text
    • http://musicandyouapp.com/webupload/editorimg/files/71438032311.pdfIn PDF document text
    • https://drbumbnursinghome.in/ckfinder/userfiles/files/toxedavizozi.pdfIn PDF document text
    • http://www.tiande-global.com/ckfinder/userfiles/files/99657369029.pdfIn PDF document text
    • http://xn--76-6kca8aqc6c.xn--p1ai/pic/userfile/73693706412.pdfIn PDF document text
    • https://bank-kredit.at/ckfinder/userfiles/files/kujotazoko.pdfIn PDF document text
    • http://yongchengtech.com/uploads/files/202109071425104589.pdfIn PDF document text
    • https://www.cukoyem.com.tr/wp-content/plugins/super-forms/uploads/php/files/bi03lpuopsekf6akd863k2jfk0/gepodaxukojofonopebimovin.pdfIn PDF document text
    • http://gpmpoolandspa.com/ckfinder/userfiles/files/62346932130.pdfIn PDF document text
    • https://wscnaturalhealings.com/wp-content/plugins/super-forms/uploads/php/files/bef363fbffd2b11b164ddf3973d93c93/lawipidokigumufut.pdfIn PDF document text
    • http://machulski.com/public/file/98074270398.pdfIn PDF document text
    • https://www.nhabe.com.vn/ckfinder/userfiles/files/sixogikakozegikasejomim.pdfIn PDF document text
    • http://relaxzenter.com/uploads/files/95531027724.pdfIn PDF document text
    • https://www.caissedesecolesdu5eme.fr/backoffice/ckfinder/userfiles/files/83131458706.pdfIn PDF document text
    • https://budgetparking.ca/admin/uploads/file/38463363032.pdfIn PDF document text
    • http://erfansari.ir/ckeditor/files/files/39341715540.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/Om9ozkHLxGw/uplcv?utm_term=bronfenbrenner+developmental+theoryPDF 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_off0000d362.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD362 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000eb74.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEB74 17276 bytes
SHA-256: 1545d7761a95fcdd36b35543aa75dfc44cf2bfa4cd14283b1ceb5eef5321b1d6
font_02_sfnt_off000117c9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x117C9 10876 bytes
SHA-256: 367a1251b87da804b9b6c0573e2f6ae6df5279cd43082b9fa23464376df265c9