Malicious PDF — malware analysis report

Static analysis result for SHA-256 51704c8cca8eeb31…

MALICIOUS

PDF

91.3 KB Created: 2021-07-20 06:23:25 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: 66ebf231bca5e58399b12c3de2ead0c8 SHA-1: 00287542b58d55dae0ed73c46f024deaf934fc7d SHA-256: 51704c8cca8eeb31d42b9022e033c9a6b5451a57ce9187af57d1f07d4751bf79
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF document was flagged as malicious by ClamAV and an ML classifier. The file embeds a large number of external links characteristic of an SEO link farm, many hosted on compromised CMS upload directories. Specific URLs and indicators for this sample are listed in the indicators section.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9822

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.brennholz-heinlein.de/wp-content/plugins/formcraft/file-upload/server/content/files/1609c8e2ba151f---32118301557.pdf In PDF document text
    • https://noks.cz/wp-content/plugins/formcraft/file-upload/server/content/files/160af577503005---nunusumugapumapusozuka.pdfIn PDF document text
    • https://www.baptistenhardenberg.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1609ec9edccabe---budatojuterenekuvisuvikod.pdfIn PDF document text
    • http://longarmacademy.net/fckeditor/userfiles/file/zivubunuvono.pdfIn PDF document text
    • https://www.sesc.com.ua/wp-content/plugins/super-forms/uploads/php/files/uch1tee5ejhje0ml2t4b1ln537/togivuvegosezupemuz.pdfIn PDF document text
    • https://robinio.de/wp-content/plugins/super-forms/uploads/php/files/spfgjafldt108ivf5gakdtqvbq/13574630288.pdfIn PDF document text
    • http://www.ettermanenterprises.com/ckfinder/userfiles/files/76729799063.pdfIn PDF document text
    • http://www.1atlanticfunding.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ae9817700df---banabobikofudikifi.pdfIn PDF document text
    • http://zbraneklapka.cz/ckfinder/userfiles/files/71052028936.pdfIn PDF document text
    • http://analogsys.com/uploaded/file/128651015460d7bf6fe30f4.pdfIn PDF document text
    • http://constantemails.com/userfiles/file/1625255215fatenexu.pdfIn PDF document text
    • https://uaqbakery.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606c96e899267---rupufigivisanosaromoz.pdfIn PDF document text
    • https://burragebrothers.com/demo/jolie/beta/userfiles/files/pazedenabowuwodoxixopep.pdfIn PDF document text
    • https://www.numberoneporthill.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1608e714d7c59c---47833280262.pdfIn PDF document text
    • https://braviengenharia.com.br/wp-content/plugins/super-forms/uploads/php/files/6tl7p42cr8vd2qssajni4d80pp/4327294903.pdfIn PDF document text
    • https://www.azembay.com/wp-content/plugins/super-forms/uploads/php/files/8o18umvv6bqdthlohf4hah12m5/99439364334.pdfIn PDF document text
    • http://mas.vacations/wp-content/plugins/formcraft/file-upload/server/content/files/1608076d52f501---botogiwobotubeba.pdfIn PDF document text
    • https://kfz-gutachter-oliver-schiller.de/wp-content/plugins/formcraft/file-upload/server/content/files/1607d18d47a9b2---wobero.pdfIn PDF document text
    • http://www.fullertherapy.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608277a1da57f---92141221658.pdfIn PDF document text
    • http://orhs86reunion.com/clients/6/67/6744625166a0df26c7abb40948833271/File/negovosilanekukuwe.pdfIn PDF document text
    • http://mtsskzy.com/userfiles/file/rajuvurokerupogofekuxusaw.pdfIn PDF document text
    • https://www.coconutlodge.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c5721f8f46f---sirovujagunigizad.pdfIn PDF document text
    • https://kermiradiatoriai.lt/images/files/63607886687.pdfIn PDF document text
    • http://www.adanakursmerkezi.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a67e3666a23---43619225373.pdfIn PDF document text
    • http://krindustria.com.br/site/wp-content/plugins/formcraft/file-upload/server/content/files/16076777174fa9---42690631726.pdfIn PDF document text
    • http://medtravel.pro/images/hand_uploaded/files/470923215.pdfIn PDF document text
    • https://alrashed-alsaleh.com/userfiles/files/35103907820.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/3vuEKuznOb8/uplcv?utm_term=meredith+and+mantel+project+management+pdfPDF 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_off00010000.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10000 17760 bytes
SHA-256: ab41ac6c024a160aa9835a14a4b207ca03ece43244de9fac8c8f0c064f69af53
font_01_sfnt_off00012e4d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12E4D 11020 bytes
SHA-256: b7738cbec45213f90935efb8ee1ccf983e8c6f75063d71e3fa5e231dce5082aa
font_02_sfnt_off00014773.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14773 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1