Malicious PDF — malware analysis report

Static analysis result for SHA-256 8646c1695fa72c95…

MALICIOUS

PDF

123.7 KB Created: 2021-06-30 19:15:37 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-14
MD5: ab5db6fa3769f8c2511432c0d4a4a405 SHA-1: a2f519dd2293a27bec94db108483780a832797fc SHA-256: 8646c1695fa72c95bc17dc118af31beee3b7192692d48844bb0adc201b5ff697
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF that contains a large number of links, many of which point to compromised websites and disposable hosting. The ML classifier and ClamAV detection strongly indicate maliciousness. The PDF_SEO_DISPOSABLE_LINK_FARM heuristic suggests the document is designed to host a link farm, likely for SEO manipulation or to distribute malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9972

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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 https://www.rath-catering.de/wp-content/plugins/formcraft/file-upload/server/content/files/160a33c3af0e9a---putizixamozebuvofa.pdf In PDF document text
    • https://profipreklady.cz/www/ckfinder/userfiles/files/86907227693.pdfIn PDF document text
    • http://tipiland.net/upload/file/nagoxasopoduneju.pdfIn PDF document text
    • http://www.itbaloch.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c542615b827---werujofarul.pdfIn PDF document text
    • http://www.cascinasorigherio.it/wp-content/plugins/formcraft/file-upload/server/content/files/160a9d0bfa772e---49268703941.pdfIn PDF document text
    • https://buddingheights.org/wp-content/plugins/formcraft/file-upload/server/content/files/16092a241b7a49---jikimesikubisovomewojaket.pdfIn PDF document text
    • http://bfr-bialapodlaska.pl/userfiles/file/69957773944.pdfIn PDF document text
    • http://reanda.com/jingkelun/userfiles/files/20210626060648.pdfIn PDF document text
    • https://xo-sound.ru/userfiles/file/sevilatimokixi.pdfIn PDF document text
    • http://reiki-roots.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160b301ff72d5d---nokomijurapukukerowot.pdfIn PDF document text
    • https://space1500.com/wp-content/plugins/super-forms/uploads/php/files/7ad5acfa227827922e354cc816bcc3ce/povutemipogubonoluxanakab.pdfIn PDF document text
    • https://www.waterlooarmsnewforest.co.uk/wp-content/plugins/super-forms/uploads/php/files/0e59eda060b66bbcd26aae1cad827b57/wuzezawakenibijomixodu.pdfIn PDF document text
    • https://puertoestereo.com/wp-content/plugins/super-forms/uploads/php/files/l42k9lichpoequi9pk9ld8jp62/mozuta.pdfIn PDF document text
    • https://btegypt.com/file/turepolusezi.pdfIn PDF document text
    • https://1sis.com/wp-content/plugins/formcraft/file-upload/server/content/files/160cd68247c3ef---mopenorovim.pdfIn PDF document text
    • https://gift-edu.ru/wp-content/plugins/super-forms/uploads/php/files/b5418145475c9308c8838f3f6d405847/5112181531.pdfIn PDF document text
    • http://krevue.cz/UserFiles/File/95712801491.pdfIn PDF document text
    • http://bezpieczna-strefa.pl/wp-content/plugins/super-forms/uploads/php/files/697cb1939a524b3bd6ce27e0a1220dd9/67025076350.pdfIn PDF document text
    • https://rjiminfra.com/wp-content/plugins/super-forms/uploads/php/files/59bf290e91e4ec3dacb98c458d075cfc/jobimidowazelurebubekeror.pdfIn PDF document text
    • http://gayaarchi.com/userfiles/file/20210518155634.pdfIn PDF document text
    • http://hndgyl.com/v15/Upload/file/2021630427551854.pdfIn PDF document text
    • https://cardion.dk/gfx/fckimages/file/78578055132.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/6naE_Nh8_CY/uplcv?utm_term=series+with+reese+witherspoon+nicole+kidmanPDF 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_off00017f62.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x17F62 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00019779.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x19779 11032 bytes
SHA-256: dbf5dc59b0c5f8c491fc07cc1f89e688bd9bef19b135ef5cdc67f76fdd2a9b34
font_02_sfnt_off0001b0f2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1B0F2 18460 bytes
SHA-256: 949f28e76048c07c069bb04526622260c1f848fc780a0e13bad37ccae24d6fdd