Malicious PDF — malware analysis report

Static analysis result for SHA-256 4b5db71fb640cfb6…

MALICIOUS

PDF

127.6 KB Created: 2021-09-05 14:28:34 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: 407abff4f0bba63ac23ee3998a347662 SHA-1: 5fe85c2a596a08a484dd15622dd4d45e0042a14a SHA-256: 4b5db71fb640cfb6939ece503b3b625628aa47a1effe6a6aac6cfd1f0414b60e
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript and numerous external URIs, many of which point to compromised WordPress sites. These links likely serve as a lure to download further malicious content or redirect to phishing pages. The ML classifier and ClamAV detection strongly indicate malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9987

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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://coretry.ru/uplcv?utm_term=multivariate+statistical+process+control+with+industrial+applications+pdf PDF link annotation
    • https://studiogreenwich.ru/wp-content/plugins/super-forms/uploads/php/files/2c71949015e7717b967fe8abd0cd1fee/40462295544.pdfIn PDF document text
    • http://www.suffaheducation.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608250e3e1aaf---35472499231.pdfIn PDF document text
    • https://www.americansummercamps.com/wp-content/plugins/formcraft/file-upload/server/content/files/160834b085857b---witemuvag.pdfIn PDF document text
    • http://www.empresasdelimpeza.info/wp-content/plugins/formcraft/file-upload/server/content/files/16073005e55273---67962512713.pdfIn PDF document text
    • https://www.focus.mu/wp-content/plugins/super-forms/uploads/php/files/9e8a14de4e3d32cc5de40975ff607012/somuwuzilare.pdfIn PDF document text
    • https://microfocus-realize2020mea.com/wp-content/plugins/super-forms/uploads/php/files/f227ce68074ab9c73bf75b49ce16ae56/20125756449.pdfIn PDF document text
    • http://dinskayarealty.ru/media/file/rugisugojosajilan.pdfIn PDF document text
    • https://dmddsgn.com/wp-content/plugins/super-forms/uploads/php/files/c6121d3168cbb29de72a223198243966/350582460.pdfIn PDF document text
    • http://gostinica-domodedovo.ru/files/lidowoju.pdfIn PDF document text
    • https://cornwallstaffagency.com/userfiles/file/42875821332.pdfIn PDF document text
    • http://www.toptehnik.si/images/nobenuvowutikusoj.pdfIn PDF document text
    • https://jbdclothiers.net/emailer/userfiles/file/murejosobenidimi.pdfIn PDF document text
    • http://dochoiotovn.com/uploads/userfiles/file/sugetimawaj.pdfIn PDF document text
    • https://www.alapan.org/fckimages/file/bewunugusegalobewajo.pdfIn PDF document text
    • http://structurecreative.com/wp-content/plugins/formcraft/file-upload/server/content/files/160810fc39be7c---jiwirajuwixuwafe.pdfIn PDF document text
    • http://www.pointcookelectrician.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160a1aec1a32d9---fopasaxelizugida.pdfIn PDF document text
    • https://www.brunosistemi.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608c04b2d9bff---sarikavibufuke.pdfIn PDF document text
    • https://patidarpalanpur.com/web/k/main_admin/ckfinder/userfiles/files/zasipiluzibojiva.pdfIn PDF document text
    • http://run2endalz.org/clients/2/2b/2b4973775a35d8819257a28a16fdea67/File/gofux.pdfIn PDF document text
    • https://miguktour.com/FileData/ckfinder/files/20210825_679719F2CACF52F6.pdfIn PDF document text
    • https://hylyt.co/wp-content/plugins/super-forms/uploads/php/files/f8ffd6d5541cdc657ff46613bc46d51b/51285918045.pdfIn PDF document text
    • http://antwerp-rentals.com/wp-content/plugins/formcraft/file-upload/server/content/files/160860ce93aada---risukavanetinuliwom.pdfIn PDF document text
    • https://www.hemingway.bg/app/templates/js/ckfinder/userfiles/files/zofosalizosa.pdfIn PDF document text
    • http://rivucota.com/upload/files/soretunuwazajipurib.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_off00018752.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x18752 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00019f69.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x19F69 10964 bytes
SHA-256: dc3cb2a2bc628d1bb1b656123750a4e8a7444b2b4c6bcfee92e7df8502d65e8b
font_02_sfnt_off0001b8d8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1B8D8 20528 bytes
SHA-256: 3a86345b818c53d7428bee3e2c665d3ea22622ecc84f84d7d17d3990e25edff2