Malicious PDF — malware analysis report

Static analysis result for SHA-256 b551850e1bcb28c2…

MALICIOUS

PDF

83.1 KB Created: 2021-09-12 05:02:10 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 8433413c8eeeeda467c79b37dd13d9b7 SHA-1: f36bdd1cb23c4b47bd2892564a40b77c2e074d50 SHA-256: b551850e1bcb28c213493d26e0ea5e8c006964548e1182db2bda504f7c96d8ff
156 Risk Score

Malware Insights

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

The PDF document contains a link farm pointing to multiple compromised WordPress sites and disposable domains, indicating a phishing or malware distribution attempt. The ML classifier and ClamAV detection strongly suggest malicious intent. The embedded URLs are likely used to redirect users to malicious content or download further payloads.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

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://www.conkite.com/wp-content/plugins/super-forms/uploads/php/files/5254caa7b668834499859fef6a35b207/sufamejub.pdf In PDF document text
    • http://memsports.com.br/admin/libs/ckeditor/ckfinder/files/84488009101.pdfIn PDF document text
    • http://dermalab.pl/userfiles/file/46709490751.pdfIn PDF document text
    • https://easy2ticket.com/upload/files/worazijudopisenevonakege.pdfIn PDF document text
    • https://nuregio.de/wp-content/plugins/formcraft/file-upload/server/content/files/1613d4adc401af---nabiremeziludabuxonunop.pdfIn PDF document text
    • https://cncostruzioni.com/userfiles/file/8589006492.pdfIn PDF document text
    • https://mimpishio2.net/contents/files/suvawawajademawil.pdfIn PDF document text
    • https://mlbcsimleague.com/ckfinder/userfiles/files/85913860767.pdfIn PDF document text
    • http://www.nuricomuvakfi.org/wp-content/plugins/super-forms/uploads/php/files/83qquiu5fh945v5ultvb0kdfi7/luseki.pdfIn PDF document text
    • https://auf.vn/wp-content/plugins/super-forms/uploads/php/files/14rb7j8ecalbnqbm8fagub78e5/bodaranitojilozepev.pdfIn PDF document text
    • http://botosani.ro/img/uploads/file/96831101200.pdfIn PDF document text
    • http://evevoyance.fr/adh/.-/file/ripalap.pdfIn PDF document text
    • http://www.museopizarra.com/ckfinder/userfiles/files/63463646177.pdfIn PDF document text
    • https://poulinstrapscan.com/userfiles/file/46948318618.pdfIn PDF document text
    • https://stichtingech.org/ckfinder/userfiles/files/lupefalajonamagaxipipumal.pdfIn PDF document text
    • https://weyergans-hcc.lv/userfiles/file/76150653598.pdfIn PDF document text
    • http://johnmichaelharrisonlaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/bitotefufubazojulo.pdfIn PDF document text
    • https://ctcitsupport.com/media/files/nedasulajejelotebazew.pdfIn PDF document text
    • http://daehwa.info/uploaded/file/47527287849.pdfIn PDF document text
    • http://mastervin.ru/files/file/towilak.pdfIn PDF document text
    • http://davobio.com/upload/files/54097716938.pdfIn PDF document text
    • http://sushigonewildtogo.com/uploads/files/2461603100.pdfIn PDF document text
    • https://gulfsupremesa.com/ckfinder/userfiles/files/jegirodedorukavi.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/PmAiG5ZyT-k/uplcv?utm_term=schedule+texts+androidPDF 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_off0000de16.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDE16 18608 bytes
SHA-256: eb60a981f01fdfd6b85b354bb36b633eebe051b85b512c76d206a14ec6219b5e
font_01_sfnt_off00010e2e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10E2E 10744 bytes
SHA-256: e5954bfc4370b60cfcff00dffc30347def7c53821899a7e6e8a620ff4a941e41
font_02_sfnt_off000126d5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x126D5 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1