Malicious PDF — malware analysis report

Static analysis result for SHA-256 1d35d57e2b4ac3d8…

MALICIOUS

PDF

87.1 KB Created: 2021-07-02 02:08:51 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-21
MD5: 664b3628a69e9d288db375760de62098 SHA-1: 019279b49cc38f64cba67164e7a201823768a443 SHA-256: 1d35d57e2b4ac3d80b8b8f55e5eb60744e8ca542fafa4d2ac96e47dff7a71af9
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It functions as a link farm, with numerous embedded URLs pointing to compromised WordPress upload directories and other disposable hosting. These links likely lead to further stages of infection or phishing attempts.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9835

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 http://www.suffaheducation.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a873474ffc2---rilabedirin.pdf In PDF document text
    • http://adabaskimerkezi.com/upload/file/9280331597.pdfIn PDF document text
    • https://refour.eu/wp-content/plugins/super-forms/uploads/php/files/c99fde28c7c7ed97ceee2c5b6bafdf2c/15747827975.pdfIn PDF document text
    • http://chicagohalo.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bbdd1bd0dbc---31128593944.pdfIn PDF document text
    • https://dermo.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608df818b7f81---xikitosogoj.pdfIn PDF document text
    • http://famcareconnect.org/wp-content/plugins/formcraft/file-upload/server/content/files/160a720498703f---bodarifuluwazifube.pdfIn PDF document text
    • https://ventana-sur.com/wp-content/plugins/formcraft/file-upload/server/content/files/160894b343f7bc.pdfIn PDF document text
    • http://progetec.org/userfiles/files/zanotexateduwanu.pdfIn PDF document text
    • https://www.elektrobetrieb-scholz.de/wp-content/plugins/formcraft/file-upload/server/content/files/16094bfd81fbf3---39591199026.pdfIn PDF document text
    • https://simovi.mx/wp-content/plugins/formcraft/file-upload/server/content/files/160a4108c3f685---66315503084.pdfIn PDF document text
    • http://www.iqubz.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607ee6ec82e10---81275993833.pdfIn PDF document text
    • http://files.ibiza-ferien.de/file/74732171527.pdfIn PDF document text
    • https://miamivanservice.net/wp-content/plugins/formcraft/file-upload/server/content/files/1606cbc7040de1---91738164001.pdfIn PDF document text
    • https://menu2uplus.com/images/file/93855233328.pdfIn PDF document text
    • https://mytopics.it/uploads/file/kotib.pdfIn PDF document text
    • https://miamivanservice.net/wp-content/plugins/formcraft/file-upload/server/content/files/1607b3bdbaada8---5689280803.pdfIn PDF document text
    • http://www.hcibatiment.fr/wp-content/plugins/formcraft/file-upload/server/content/files/160c1a64055fae---rividoxedusuzefolodinuwew.pdfIn PDF document text
    • https://rlmahtani.com/userfiles/files/pezebezuke.pdfIn PDF document text
    • https://bodegoncriollo.com/userfiles/file/lufimewebujidujojokaxe.pdfIn PDF document text
    • https://dacinsara.ro/fckfiles/file/nobax.pdfIn PDF document text
    • http://brighterhealthcare.co.uk/wp-content/plugins/super-forms/uploads/php/files/1r9jkgvur4qjet7lqj15ljgs56/rerapinukamefexexurimu.pdfIn PDF document text
    • http://www.primalegal.eu/wp-content/plugins/super-forms/uploads/php/files/bainp81j76r7hal4bslojomt21/gozewifubaxobi.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609db17684610---35858631083.pdfIn PDF document text
    • http://associacaoguainumbi.org.br/wp/wp-content/plugins/formcraft/file-upload/server/content/files/1607372e0902ea---23625254820.pdfIn PDF document text
    • http://adance0112.com/upfile/editor/file/60383193539.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/GLLx1DTH0VQ/uplcv?utm_term=fall+act+dates+2020PDF 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_off0000f3d4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF3D4 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00010beb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10BEB 10168 bytes
SHA-256: 83aba0c56830a7d172d48fc0aeb6903d9292095746a06a039f3b76a3f880940b
font_02_sfnt_off000122e4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x122E4 17116 bytes
SHA-256: d7cea79a7dbe83ad00a5bb274944a1e9dec177a869251d338bc0f35cc88a6d24