Malicious PDF — malware analysis report

Static analysis result for SHA-256 ce876a16455b0edc…

MALICIOUS

PDF

77.1 KB Created: 2021-09-08 23:43:23 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: db1555a740bf49ba2f149278c7773753 SHA-1: 9d0a4b548498e8bc02e3b0b16af4c3c280f48709 SHA-256: ce876a16455b0edc77964fb2e41b92d06b5ba3b7c1854ac17af3e1204f952624
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file was flagged by multiple heuristics and a machine learning classifier as malicious, with ClamAV identifying it as Pdf.Phishing.Trojan. The numerous embedded URLs point to compromised WordPress sites and other domains, suggesting a link farm designed to redirect users to malicious content. The presence of PDF_SEO_DISPOSABLE_LINK_FARM and PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM heuristics indicates a sophisticated effort to obscure the true destination of the links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9908

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://smidgel.ru/uplcv?utm_term=no+root+tethering PDF link annotation
    • https://www.alugutader.fr/ckfinder/userfiles/files/fibilubisemupoz.pdfIn PDF document text
    • https://nbretail.com.vn/ckfinder/userfiles/files/pizupo.pdfIn PDF document text
    • https://chameleoncoupons.com/adgprocessing/uploads/files/nivuwitu.pdfIn PDF document text
    • http://e-photo.lv/ckfinder/userfiles/files/11077244378.pdfIn PDF document text
    • https://bykevin.com/wp-content/plugins/super-forms/uploads/php/files/8b2e4a151ecc687129ac21d3678e22d5/4682326869.pdfIn PDF document text
    • http://kleiberit.ru/files/file/runow.pdfIn PDF document text
    • http://all-premium.com/user_file/files/sajav.pdfIn PDF document text
    • http://boston.pl/fck_pliki/file/rurobelij.pdfIn PDF document text
    • http://www.yevres.fr/ckfinder/userfiles/files/92695449586.pdfIn PDF document text
    • https://www.sevgiliyevideo.net/wp-content/plugins/formcraft/file-upload/server/content/files/16136f84ab27ec---nijogeredirujovituwejakax.pdfIn PDF document text
    • http://hk888.edo2008.com/com/comimg/file/20210909_005626_167.pdfIn PDF document text
    • https://ambient-interier.cz/files/files/dewepun.pdfIn PDF document text
    • https://forumhotel.by/wp-content/plugins/super-forms/uploads/php/files/ut7o70fe8ccokgkgvc70fm3ri0/84343045329.pdfIn PDF document text
    • http://phutungvespaco.com/luutru/files/lubulokawovitakoxop.pdfIn PDF document text
    • https://jaunimodienos.lt/wp-content/plugins/super-forms/uploads/php/files/j9fauffjarmfag4h7al7massjd/76767135126.pdfIn PDF document text
    • https://holcom-wd.holcom.vn/webroot/img/files/wikefatusofibasixixoba.pdfIn PDF document text
    • http://colorfulmedia.de/fotki/fotki/file/57136946173.pdfIn PDF document text
    • https://andana.us/files/files/xowaxebinuxosugoli.pdfIn PDF document text
    • http://www.majorisinvestimentos.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/161339e42749b5---4160252391.pdfIn PDF document text
    • http://dermatologomiguelgallego.com/miguel/fck/file/63916443845.pdfIn PDF document text
    • https://euronet.stonavka.cz/webpagebuilder/ckfinder/userfiles/files/fipibunipas.pdfIn PDF document text
    • https://ojazzdance.fr/userfiles/file/54492593121.pdfIn PDF document text
    • http://zgic.ru/!upload/files/9616125549.pdfIn PDF document text
    • https://mastirz.com/userfiles/files/67779841285.pdfIn PDF document text
    • https://llibreriaha.com/img/events/file/labaferejilofejesadesur.pdfIn PDF document text
    • http://dom-nenilovo.ru/wp-content/plugins/super-forms/uploads/php/files/aa2040943cfc8f04b06dea7e619992ce/16565130754.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_off0000caa9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCAA9 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000e2bf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE2BF 9988 bytes
SHA-256: 3c3295319b6f925f339ac0c011cc8088ebb197249fc85f9120ee9af3cbcc7102
font_02_sfnt_off0000f8d0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF8D0 17816 bytes
SHA-256: b43b44d1cd28f37422c92ee1110a9c185483bf6a4f14f3487afc5bf25f9bc69b