Malicious PDF — malware analysis report

Static analysis result for SHA-256 25d0da366dfcbc3d…

MALICIOUS

PDF

71.6 KB Created: 2021-09-29 11:57:54 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-23
MD5: ae73c1fa75927100ee89042dd43c092e SHA-1: 577da5800d888f324e7a122cc02206b261d261f6 SHA-256: 25d0da366dfcbc3dc23b1e22e0c78684e0d18cfaf452b56ee9fa9a6acbc18bc8
176 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The file is a PDF document flagged by ClamAV as Pdf.Phishing.Trojan and by an ML classifier as malicious. Heuristics indicate it functions as a link farm and contains a callback phishing lure, prompting users to call a phone number. While no scripts were directly extracted, the PDF structure and embedded URLs suggest an attempt to redirect users to malicious sites or initiate fraudulent phone calls.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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://ontis.sk/editor_uploads/system/files/34198100002.pdf In PDF document text
    • https://101doctor.com/uploads/ckfiles/files/61382703bdfeb.pdfIn PDF document text
    • http://streetnn.ru/data/upload/ck/files/82469319367.pdfIn PDF document text
    • https://malimbe.africa/wp-content/plugins/super-forms/uploads/php/files/9af60f9f9eb6414a33001d179b521c35/33992927650.pdfIn PDF document text
    • https://egyptsuntours.com/userfiles/files/wawomowitedogi.pdfIn PDF document text
    • http://proxima-online.it/public/file/biwebimaberojakudu.pdfIn PDF document text
    • http://modellszerviz.hu/userfiles/file/288281421.pdfIn PDF document text
    • http://www.putnamtaxi.net/wp-content/plugins/formcraft/file-upload/server/content/files/16141db4dbc2e4---91097222940.pdfIn PDF document text
    • https://www.inter-tube.co.uk/wp-content/plugins/super-forms/uploads/php/files/6e5b6c9ce025026a3e298869ebff6a2d/posepodokopuzipixe.pdfIn PDF document text
    • http://intrinhgia.com/admin/webroot/upload/image/files/wunusasa.pdfIn PDF document text
    • http://schroniskoorzechowce.pl/ckfinder/userfiles/files/feruxef.pdfIn PDF document text
    • http://turnyras.lt/Files/file/fodelulositapavamavek.pdfIn PDF document text
    • https://www.dentaltaxpros.com/wp-content/plugins/super-forms/uploads/php/files/f97cf8d714f9c32e7e840c239ae50ad0/3118024156.pdfIn PDF document text
    • http://tipsclubcr.com/campannas/file/18963795121.pdfIn PDF document text
    • http://clinicaveterinariasangiacomo.it/userfiles/files/52167490669.pdfIn PDF document text
    • https://alienaquatics.com/home/gb/public_html/ckfinder/userfiles/files/82247274670.pdfIn PDF document text
    • https://aathichudi.org/userfiles/file/nunanakedan.pdfIn PDF document text
    • https://kalimati.in/userfiles/file/66962523722.pdfIn PDF document text
    • http://gartenmessebau.de/uploads/files/33539751463.pdfIn PDF document text
    • http://namhungholdings.com/uploads/ckfinder/files/62765089436.pdfIn PDF document text
    • http://naturabliskociebie.pl/userfiles/file/dutadikoxidasi.pdfIn PDF document text
    • https://desense.eu/uploads/wysiwyg/files/xegegubewamazemidinobe.pdfIn PDF document text
    • http://altinay-law.com/images/file/zubuwo.pdfIn PDF document text
    • https://radio-clipa.ro/userfiles/file/vufakefimefuzusosigubiva.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/A3Ryygt5BCM/uplcv?utm_term=free+live+tv+apps+like+mobdroPDF 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_off0000b4e4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB4E4 17148 bytes
SHA-256: b6780d1866c748b2ce57ff347b59fa0b00de576ef666ea1c2913b6e20e34936f
font_01_sfnt_off0000dffd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDFFD 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000f814.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF814 10724 bytes
SHA-256: 5829c346e6be0c72d572ec4f52650826cd0b7450aec7422309c758018c1da569