Malicious PDF — malware analysis report

Static analysis result for SHA-256 51d179a371437741…

MALICIOUS

PDF

125.1 KB Created: 2021-07-31 23:57:35 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 56d087821e5123866fb811643f3118f6 SHA-1: 2101db157b492fe9718d02393bb1d2da338cd5a6 SHA-256: 51d179a3714377412305d05eb6ffbfc748c360ccafaeb6bfe70ef81f946778c7
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file was detected as malicious by ML classifiers and ClamAV, indicating a phishing or malware distribution attempt. It functions as a link farm, with numerous embedded URLs pointing to compromised CMS upload directories. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' suggests these links are on disposable hosting, likely to evade detection and host malicious content. While no scripts were explicitly extracted, the nature of the link farm and the ML detection strongly suggest an intent to redirect users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9988

Heuristics 7

  • 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.
  • Urgency / deadline lure low SE_URGENCY_LURE
    Document contains urgency or deadline language ('account will be terminated', 'action required within 24 hours', etc.) — useful context, but low-signal without other findings
  • 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://springswellness.net/wp-content/plugins/formcraft/file-upload/server/content/files/16081d440c9b20---21911531217.pdf In PDF document text
    • https://sandalyecenneti.com/wp-content/plugins/super-forms/uploads/php/files/qtbcd30lcrh7kklm96lckp8njv/watevazukitemofilaniluzi.pdfIn PDF document text
    • http://novaserv.com/wp-content/plugins/formcraft/file-upload/server/content/files/16086f050477f3---duzupabulotifosetekoku.pdfIn PDF document text
    • http://zkpower.net/upload/files/pazetem.pdfIn PDF document text
    • https://michaels-limo.com/wp-content/plugins/formcraft/file-upload/server/content/files/16100ac538eaf5---buxazefiwefisa.pdfIn PDF document text
    • http://timandlor.com/userfiles/file/vimisosiwigejaxe.pdfIn PDF document text
    • http://www.kliningstroy.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1606e3608e6e97---vorusogipexizevotuwajobax.pdfIn PDF document text
    • http://energo-winstal.pl/userfiles/file/sikiporogepulemevane.pdfIn PDF document text
    • http://ecofincas.net/ckfinder/userfiles/files/38586270498.pdfIn PDF document text
    • https://www.couleurs-et-jardin.fr/wp-content/plugins/formcraft/file-upload/server/content/files/160b2912cb89f6---12085188524.pdfIn PDF document text
    • http://erbilsunhotel.com/wp-content/plugins/super-forms/uploads/php/files/doc291bcllkih1asvggfmktp06/98268322722.pdfIn PDF document text
    • https://dienlanhhonganh.com/images/pic/file/52133181577.pdfIn PDF document text
    • https://ost-fogging.com/upload/files/lesoliwuvetezigexef.pdfIn PDF document text
    • https://www.sgestrecho.es/wp-content/plugins/formcraft/file-upload/server/content/files/160f0acf1992a8---57707728090.pdfIn PDF document text
    • http://sqx.cc/upImgFile/file/20210514091108.pdfIn PDF document text
    • https://adbetelparaguay.com/wp-content/plugins/super-forms/uploads/php/files/64b4b0e25ee640943d8cfbd43f5a6cd9/vibipekutudatugo.pdfIn PDF document text
    • https://webtechnocrats.com/upload/file/jokebuzaviku.pdfIn PDF document text
    • https://desertflying.club/wp-content/plugins/formcraft/file-upload/server/content/files/16087c496741e3---pixiko.pdfIn PDF document text
    • http://magogaralbamoble.com/galeria/files/45862826408.pdfIn PDF document text
    • http://zelene-centrum.cz/webpagebuilder/ckfinder/userfiles/files/96399464820.pdfIn PDF document text
    • http://jucal.es/images/file/27076678342.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609d6e3a29a16---pavogapetige.pdfIn PDF document text
    • http://helderlive.nl/ckfinder/userfiles/files/zewud.pdfIn PDF document text
    • http://c2ctrading.org/cms_upload/files/38324036986.pdfIn PDF document text
    • https://cmsschoolkg.org/userfiles/file/69727203807.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/ngfLrbzwjls/uplcv?utm_term=a+christmas+carol+charles+dickens+stave+1+summaryPDF 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_off0001821f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1821F 11040 bytes
SHA-256: 82dcfae917f32fdea26deec05d9c1cc5524d836b97a63f86e9c9900945516603
font_01_sfnt_off00019bc3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x19BC3 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0001b3d5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1B3D5 19692 bytes
SHA-256: bfb612d21451024c3952b3f1e9332117ffbf30b2a8043b2cebd62ea75feec974