Malicious PDF — malware analysis report

Static analysis result for SHA-256 b4d40d994ad792c3…

MALICIOUS

PDF

81.2 KB Created: 2021-09-15 01:13:29 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 72b6cdd9dd0834c59545543d474377ff SHA-1: 8094b65da85fdc06e1fef7251bb76863a4e105bb SHA-256: b4d40d994ad792c33998c53ac45b839d38d8b916e97c520fd958768b3040a004
176 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF containing a link farm pointing to various PDF files hosted on potentially compromised or disposable domains. The 'SE_CALLBACK_LURE' heuristic suggests a phishing or tech-support scam context, aiming to trick users into downloading further malicious content. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for delivering a phishing payload or malware.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9911

Heuristics 7

  • 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.
  • Callback phishing phone lure medium SE_CALLBACK_LURE
    Document asks the user to call a phone number in billing, refund, subscription, fraud, or security context — consistent with callback phishing or tech-support scam patterns. Suppressed for legitimate-issuer (IRS/gov/official-form) documents that carry no urgency or charge/dispute escalation.
  • 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://zhouzhuank.com/v15/Upload/file/2021982349151759.pdf In PDF document text
    • http://xboxheerlen.nl/userfiles/file/78947289196.pdfIn PDF document text
    • https://rmdschoolandcollege.com/wp-content/plugins/super-forms/uploads/php/files/4171a31468e2aab1acf8c73af39b9615/47066278173.pdfIn PDF document text
    • https://www.medipratik.com/wp-content/plugins/formcraft/file-upload/server/content/files/161361129124ac---42385227954.pdfIn PDF document text
    • https://masini-de-ambalat.ro/images/userfiles/35633644157.pdfIn PDF document text
    • http://amghanoi.com/images/ckeditor/files/sumikeje.pdfIn PDF document text
    • http://clubmaniacr.com/campannas/file/budokujiwojileleza.pdfIn PDF document text
    • https://carsen.sk/editor_uploads/system/files/32237614851.pdfIn PDF document text
    • http://hoitruyengiaocodocvietnam.com/uploads/image/files/mutozinamozowigomu.pdfIn PDF document text
    • https://sanaspinler.net/calisma2/files/uploads/woxupojokadukupelemazo.pdfIn PDF document text
    • http://fantasymusic.it/userfiles/files/wejosuraverawukaze.pdfIn PDF document text
    • https://mimpishiodua.com/contents/files/temakaxe.pdfIn PDF document text
    • http://www.phonefixcomo.com/wp-content/plugins/formcraft/file-upload/server/content/files/16135e3f953f5f---lezolizunidikupodemo.pdfIn PDF document text
    • http://niezapominajkowo.eu/userfiles/file/67651427525.pdfIn PDF document text
    • http://baheth24cars.com/ckfinder/userfiles/files/19447028948.pdfIn PDF document text
    • https://g4m3s-4p1-12s1.com/contents/files/dojorexojibifug.pdfIn PDF document text
    • http://madurastones.com/userfiles/file/sunepife.pdfIn PDF document text
    • http://hotelgiottotorino.com/userfiles/files/xamuk.pdfIn PDF document text
    • http://xn--22cjbbm2eyae3ehabdb4kqdtae3dxnnc1fhf.com/user_img/files/darupa.pdfIn PDF document text
    • http://autoscuolecasetta.it/userfiles/files/65352972894.pdfIn PDF document text
    • http://mtcongnghiepxanh.com/upload/fckimagesfile/nabiwado.pdfIn PDF document text
    • http://miroslaws.com/ckfinder/userfiles/files/83839769225.pdfIn PDF document text
    • https://landlorddebtadvisory.com/wp-content/plugins/super-forms/uploads/php/files/9c00c67e79f3d413e912536b084a838d/76771348992.pdfIn PDF document text
    • http://gokea.org/upload/editor/files/48693263655.pdfIn PDF document text
    • http://reylab.com/userfiles/file/pipadawitewojume.pdfIn PDF document text
    • http://bielwod.com/userfiles/file/goraxajamagesebape.pdfIn PDF document text
    • https://taksis.lv/taksis/userfiles/file/53032596484.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/cv9VXjIrmdE/uplcv?utm_term=download+drupe+pro+apkPDF 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_off0000d084.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD084 21156 bytes
SHA-256: 7f0474fce8589ab6f6ddec355a165d9d767be0b43bc0b494041ca4085cf6937d
font_01_sfnt_off000107a5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x107A5 10308 bytes
SHA-256: 34734b39b65a24015838eb9d39d0a2f59a1f96971a78c019a9f2d899b038b1f9
font_02_sfnt_off00011f03.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11F03 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1

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