Malicious PDF — malware analysis report

Static analysis result for SHA-256 84510591b7f36c05…

MALICIOUS

PDF

88.3 KB Created: 2021-08-03 07:25:36 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 23bd1c4e2409c92f28b6970fc4e1b2ee SHA-1: 07363c33d5b561c3c9467d0392fd515def30c6e0 SHA-256: 84510591b7f36c059596668e5de7d32738aa4caeb6a3ed547ae412b6a9bc4c46
156 Risk Score

Malware Insights

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

The PDF file was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, directing users to multiple external websites, some hosted on compromised WordPress installations. The embedded URLs suggest an attempt to redirect users to potentially malicious content or phishing sites.

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 https://cructi.ru/uplcv?utm_term=solucionario+mecanica+vectorial+para+ingenieros+estatica+9+edicion+capitulo+3 PDF link annotation
    • https://peilimineko.com/userfiles/file/22460908500.pdfIn PDF document text
    • https://markiza-trade.ru/admin/ckfinder/userfiles/files/zopujetudibolexik.pdfIn PDF document text
    • https://aljazeerahpetroleum.ae/userfiles/files/tuzizafepigabinatuxuwin.pdfIn PDF document text
    • http://www.victoriousintl.com/new/resource/files/41595648137.pdfIn PDF document text
    • http://studiovalentini.eu/userfiles/files/682691730.pdfIn PDF document text
    • http://darec.sk/files/files/manisowojubuv.pdfIn PDF document text
    • http://www.publicitymailing.ie/wp-content/plugins/formcraft/file-upload/server/content/files/1608df89f27703---jemak.pdfIn PDF document text
    • http://penzionnakrizankach.cz/ckfinder/userfiles/files/modonekafa.pdfIn PDF document text
    • https://spectrumohio.com/wp-content/plugins/super-forms/uploads/php/files/5c2d2a3d06a24f9e194fd9f5d8013e16/78806701274.pdfIn PDF document text
    • https://gifarlcm.com/upfiles/editor/files/61061848975.pdfIn PDF document text
    • https://gbeequestriansurfaces.com/wp-content/plugins/super-forms/uploads/php/files/rnukm8s1ru7r924pptd505hmms/vixufatarifijar.pdfIn PDF document text
    • http://dush-kz.ru/uploads/fck/file/loxogaremo.pdfIn PDF document text
    • https://centrobrands.com/wp-content/plugins/super-forms/uploads/php/files/8e07cf76ce42c746e2db24998ddce22a/noxukewijefazu.pdfIn PDF document text
    • http://www.airportlimofortlauderdale.net/wp-content/plugins/formcraft/file-upload/server/content/files/160987a019ed66---pisexijezevezivi.pdfIn PDF document text
    • http://maslag.eu/userfiles/file/27282904229.pdfIn PDF document text
    • https://aquariumfargo.com/wp-content/plugins/super-forms/uploads/php/files/496e523a10c9ce0523041cd4e4e2cbe6/81298934188.pdfIn PDF document text
    • https://gamma-electronics-eg.com/userfiles/files/kuzuloba.pdfIn PDF document text
    • https://kakvkusno26.ru/wp-content/plugins/super-forms/uploads/php/files/c8aea76b2c73f488f64b5c8e2c3e8562/6746957141.pdfIn PDF document text
    • http://odessahighschool1970.com/clients/7/70/70263b1be1b93b62200e198143f59f20/File/53117793896.pdfIn PDF document text
    • http://www.associatedomains.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a683594fe44---30256818690.pdfIn PDF document text
    • http://dymenahealthcare.com//upload/fckeditor/file/pevavadoxutukuvel.pdfIn PDF document text
    • https://goacetours.com/ckfinder/userfiles/files/66750850444.pdfIn PDF document text
    • http://decom.pro/admin/ckfinder/userfiles/files/50677007801.pdfIn PDF document text
    • http://ansatrans.ru/admin/ckfinder/userfiles/files/40399998269.pdfIn PDF document text
    • http://alphaconsultinggroup.us/vpw/images/file/33806169697.pdfIn PDF document text
    • https://nsck-cykelmotion.dk/ckfinder/userfiles/files/8773471366.pdfIn PDF document text
    • 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_off0000ebd9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEBD9 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off000103eb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x103EB 19944 bytes
SHA-256: 2fcb708654bca9871fdf87af1b0105e33c824f2fa27fe1835607cf592bc29030
font_02_sfnt_off00013604.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13604 11436 bytes
SHA-256: 8e22d46ff0d4a8cf3d1bc9fdbb65263317367d27f41f4655948562b8971dc254