Malicious PDF — malware analysis report

Static analysis result for SHA-256 4528355f7d130c79…

MALICIOUS

PDF

85.0 KB Created: 2021-06-25 19:16:35 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2026-06-05
MD5: 187fb867f2cfb228fd6a20a2c302b560 SHA-1: 5983344ea4d940b07f11fdba92ad31604b9d2ece SHA-256: 4528355f7d130c7996454ea431b9b3d08bebb41806de6af992746561c82dfab7
156 Risk Score

Malware Insights

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

This PDF file was identified as malicious by ML classifiers and ClamAV, flagging it as a phishing trojan. It contains a large number of external URIs, many of which point to compromised WordPress upload directories, suggesting it functions as a link farm to distribute further malicious content. The presence of multiple links on disposable hosting and the use of UTM parameters further indicate a phishing or spamming campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

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://wilsonbarrera.com/inicio/wp-content/plugins/formcraft/file-upload/server/content/files/160bcb4f58f930---50847223852.pdf In PDF document text
    • https://noukos.gr/wp-content/plugins/formcraft/file-upload/server/content/files/160a000278b321---jebowe.pdfIn PDF document text
    • http://tktravel.shop/FileData/ckfinder/files/20210625_94E283FF3E44700A.pdfIn PDF document text
    • https://globalclassic.org/wp-content/plugins/super-forms/uploads/php/files/t0ttpkn8u7gml8a55301endbsr/kozufanobe.pdfIn PDF document text
    • http://www.rkcomdesignservices.com/wp-content/plugins/formcraft/file-upload/server/content/files/160704d983e0c9---13331273052.pdfIn PDF document text
    • https://terravistahometeam.com/wp-content/plugins/super-forms/uploads/php/files/2aa9007c08e1912f898ac82f930c230f/35123021445.pdfIn PDF document text
    • https://www.hungarianassociation.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b9b26bf2636---38387625231.pdfIn PDF document text
    • http://caphegiabao.com/upload/fck/file/zawipik.pdfIn PDF document text
    • http://pogotowienaukowe.com/Upload/file/letakafimutofeje.pdfIn PDF document text
    • http://localhomesales.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/16073e32bcec01---9288575696.pdfIn PDF document text
    • https://www.bouwenaaneensterkwerkgeversmerk.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160c877bc2db14---tabakuredekudagibaxiw.pdfIn PDF document text
    • https://www.chartsunlimited.com.ph/wp-content/plugins/formcraft/file-upload/server/content/files/160d3cdff2ead2---36817411473.pdfIn PDF document text
    • http://artin-intranet.com/ckupload/files/togexezugusovaxepivexi.pdfIn PDF document text
    • http://amadpich.com/userfiles/file/tisenokigo.pdfIn PDF document text
    • https://www.ideaklinik.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608105ad99728---tubufurezojititorumupolew.pdfIn PDF document text
    • https://www.schroedersales.com/wp-content/plugins/super-forms/uploads/php/files/bca50dfb1989e25a819e694a0b712cbb/9687426534.pdfIn PDF document text
    • http://www.circoloaletrium.it/wp-content/plugins/formcraft/file-upload/server/content/files/160c1641247985---nonobafudezofexuzerenel.pdfIn PDF document text
    • http://www.leesii.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608183d7f31b8---388753403.pdfIn PDF document text
    • http://mirembeestate.co.ug/wp-content/plugins/formcraft/file-upload/server/content/files/160820cedebc30---80706651003.pdfIn PDF document text
    • https://velvetskin.pl/wp-content/plugins/super-forms/uploads/php/files/d3de26ad4454fdded86ecb39e41bc2cb/98855106781.pdfIn PDF document text
    • http://audiomaster.se/wp-content/plugins/formcraft/file-upload/server/content/files/1608de6095e4f7---votajeluzepovutofe.pdfIn PDF document text
    • https://alnahamgroup.com/userfiles/file/33141506204.pdfIn PDF document text
    • http://leap-egypt.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c5917e56ec5---67577071547.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/LPIa9PGmDLg/uplcv?utm_term=class+12th+business+studies+chapter+2+notesPDF 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_off0000e785.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE785 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000ff9c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFF9C 11056 bytes
SHA-256: cb4187aeaebefa1f067b38bd030a22b63cca9e408a4cf494a0e4e3799bd86dc8
font_02_sfnt_off00011922.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11922 16788 bytes
SHA-256: 3f7ccd854251d4b11190992c5a5735456f5b36910c68626dd3a106016048a7d9