Malicious PDF — malware analysis report

Static analysis result for SHA-256 c5d898823b31c1de…

MALICIOUS

PDF

80.7 KB Created: 2021-09-14 14:01:19 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: c773c320249222966a5e78e34f5ceec7 SHA-1: 0249de0ea6cd9d3f3c7045a7a4bfcdeba59df5b6 SHA-256: c5d898823b31c1de371e76bacd1319a6c4fec2e24edb35ff2d479cb16d60701c
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by ML classifiers 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 CMS uploads. While no scripts were explicitly extracted, the PDF structure and link farm behavior suggest an intent to redirect users to malicious sites, likely for phishing or further malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

Heuristics 6

  • 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.
  • 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.truckersplantparts.co.uk/ckfinder/userfiles/files/11571046340.pdf In PDF document text
    • http://studiotecnicopetrillo.eu/userfiles/files/15405591978.pdfIn PDF document text
    • http://urbanposthotel.com/admin/ckfinder/userfiles/files/zozum.pdfIn PDF document text
    • https://tecnomatec.cl/upload/file/70484828070.pdfIn PDF document text
    • http://vytvarnyobchod.cz/UserFiles/File/nositok.pdfIn PDF document text
    • http://refpecsbelvaros.hu/kepek/files/45380910896.pdfIn PDF document text
    • http://otevrel.eu/ckfinder/userfiles/files/watofolipabab.pdfIn PDF document text
    • https://glasschneider.koeln/wp-content/plugins/super-forms/uploads/php/files/kbs2f8e4oc18aarebh8c6dijrb/62857091674.pdfIn PDF document text
    • http://vnndt.com/Images_upload/files/fitolowemuluxekuninase.pdfIn PDF document text
    • http://wyadonline.com/userfiles/file/gipasabo.pdfIn PDF document text
    • http://ninda.vn/userfiles/files/kokamaxozed.pdfIn PDF document text
    • https://billionbosses.com/ckfinder/userfiles/files/vejolirenim.pdfIn PDF document text
    • http://puisan.ru/uploads/file/113181403.pdfIn PDF document text
    • http://kite-surf.sk/files/65147481704.pdfIn PDF document text
    • http://subventionsbetrug.de/wp-content/plugins/super-forms/uploads/php/files/2pq1nchvcrc8f9lt9bfad2gded/xuvakevokon.pdfIn PDF document text
    • https://speakingparrot.com/upload/ckfinder/files/42241592608.pdfIn PDF document text
    • http://fcv-bo.org/data/fcv-bo/userfiles/file/soridatumo.pdfIn PDF document text
    • https://mosoptagro.ru/wp-content/plugins/super-forms/uploads/php/files/1e92dfe0347f39450ceaaceeaf91a6df/17434140233.pdfIn PDF document text
    • http://www.skupp.pl/wp-content/plugins/formcraft/file-upload/server/content/files/16134e1fbc6686---87974857202.pdfIn PDF document text
    • http://emailreceptionist.net/userfiles/file/lubazigefusirevitovuf.pdfIn PDF document text
    • https://loyallcanada.net/editor_files/file/dukole.pdfIn PDF document text
    • http://www.hermosabeachbungalows.com/userfiles/files/14285293808.pdfIn PDF document text
    • https://mokshadhamnepal.org/userfiles/files/semibovagijudogebafeve.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/LPIa9PGmDLg/uplcv?utm_term=calls+blacklist+reviewPDF 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_off0000d882.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD882 10412 bytes
SHA-256: a5f773823e6fd6de254cab6f657566883ca1f0bb054e4ae54f0f5b1103923712
font_01_sfnt_off0000f055.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF055 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00010867.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10867 17364 bytes
SHA-256: 891e17605c412e411e79f0c259f6bf2db7eb1e01f0a994e66756879649563e74