Malicious PDF — malware analysis report

Static analysis result for SHA-256 28c3309cbcfb978d…

MALICIOUS

PDF

128.8 KB Created: 2021-07-29 18:31:17 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 4012398a7797df122590693512b24e43 SHA-1: 121dca90cb7caaa8ce922520d5664cae40a23f2f SHA-256: 28c3309cbcfb978d163e37c1177a61bb545619e12a765740594bbcebe9f4c922
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as malicious by ML classifiers and ClamAV, indicating a phishing or malicious content delivery attempt. It contains a link farm pointing to multiple domains, many of which appear to be compromised WordPress sites hosting PDF files. The presence of external URIs and link farms suggests an attempt to redirect users to malicious or phishing content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9907

Heuristics 6

  • 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.
  • 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.medicalart.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/160d7763779d1d---37244346419.pdf In PDF document text
    • https://hosvagyok.hu/userfiles/file/kokudubozafow.pdfIn PDF document text
    • https://www.diktu.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b77c7d1c815---48748951196.pdfIn PDF document text
    • http://erdivigado.hu/userkepek/file/96364979123.pdfIn PDF document text
    • http://aklond.com/UploadFilesfile///2021061913062490.pdfIn PDF document text
    • https://www.makathastaliklari.net/wp-content/plugins/formcraft/file-upload/server/content/files/1607a650ea169e---31276011384.pdfIn PDF document text
    • http://dobre-jaja.com/Upload/file/tizikuxesalozibe.pdfIn PDF document text
    • https://autosofortkauf.ch/wp-content/plugins/super-forms/uploads/php/files/1h5sjoajhp2g26nag3bl3avvjs/xukijijiba.pdfIn PDF document text
    • http://www.inhd.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1608dc10933dcd---14599714235.pdfIn PDF document text
    • https://discoverapartmentsforrent.com/wp-content/plugins/super-forms/uploads/php/files/ab55494b5d7bbdf9a5bf53e6b12ad0cf/newikipelefake.pdfIn PDF document text
    • http://pferdefreunde-brueckenhof.de/sites/default/files/userfiles/file/1672670051.pdfIn PDF document text
    • https://quatden.vn/webroot/img/files/potudekukixefa.pdfIn PDF document text
    • http://innotack.com/userfiles/files/76539916427.pdfIn PDF document text
    • https://misbahelmudii.org/ckfinder/userfiles/files/53728862436.pdfIn PDF document text
    • https://prikolnaya.com/wp-content/plugins/super-forms/uploads/php/files/be42d33937f13e38d9b4fa7bec92446a/53879933991.pdfIn PDF document text
    • https://asiastudy.in/ckfinder/userfiles/files/25306994786.pdfIn PDF document text
    • https://www.kbstephens.com/wp-content/plugins/super-forms/uploads/php/files/cb7e6cab8927031904f1d143d85d8ec9/gowek.pdfIn PDF document text
    • http://hotelbellevuepalermo.com/userfiles/files/tozodurapaxeka.pdfIn PDF document text
    • https://www.lorenzofranzone.it/wp-content/plugins/super-forms/uploads/php/files/b85001f12733ae21356e19c35d2dce2e/xajarijewokavizukepop.pdfIn PDF document text
    • https://yourlightingbrand.com/wp-content/plugins/super-forms/uploads/php/files/831178953fdeea77fc1094e45bbf267c/zilamunutiwura.pdfIn PDF document text
    • http://mygotour.com/FileData/ckfinder/files/20210528_D0830993EEC846F1.pdfIn PDF document text
    • https://cls-toronto.com/wp-content/plugins/super-forms/uploads/php/files/a4d2b3ee79b03396c17b9748240a5a5e/16959846839.pdfIn PDF document text
    • http://harrisonsfamilyreunion.com/clients/62911/File/bokobimoredak.pdfIn PDF document text
    • http://lalitas-thaimassage-spa.de/wp-content/plugins/formcraft/file-upload/server/content/files/1607c729929e47---19021506475.pdfIn PDF document text
    • https://canadianrelocation.net/wp-content/plugins/formcraft/file-upload/server/content/files/1607d143ab29a9---walaxutuguba.pdfIn PDF document text
    • http://optimus.org.au/wp-content/plugins/formcraft/file-upload/server/content/files/16086e88355800---xifojipuleranisosaridep.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/S30rS-6n6vg/uplcv?utm_term=prop+bets+for+super+bowl+2020+resultsPDF 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_off00019439.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x19439 18088 bytes
SHA-256: f38d47db40647b57a26c7e719256c00d30093716f6f5c98e348bb15d7d96bb5f
font_01_sfnt_off0001c3dc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1C3DC 10564 bytes
SHA-256: 08579b4a4e36c8093e499c1d796ad17f1087311939e3e83e56a6ee23a69774c9
font_02_sfnt_off0001dc03.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1DC03 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1