Malicious PDF — malware analysis report

Static analysis result for SHA-256 673cf51c3964a646…

MALICIOUS

PDF

109.8 KB Created: 2021-08-12 03:12:35 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-21
MD5: c56467806a1dc4b58e0d776fd9798dc0 SHA-1: d6bdfb3024b9fbe87e612a7b983ee0031be64b7d SHA-256: 673cf51c3964a6462fd6233824ba481f8ba0c93bfe01d701508babdba6cec9c3
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

This PDF file was detected as malicious by ClamAV and an ML classifier. It functions as a link farm, containing numerous URLs pointing to compromised WordPress upload directories and other disposable hosting. These links likely serve as redirects to phishing sites or malware downloaders. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, offering no direct user-facing content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9889

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://markzone.az/wp-content/plugins/super-forms/uploads/php/files/fqp3re44hh9ph8r9ee14ql98jg/44292234500.pdf In PDF document text
    • http://exoticland.bg/upload/files/files/1873627720.pdfIn PDF document text
    • https://jollytime.ru/wp-content/plugins/super-forms/uploads/php/files/8086723b3d4b753cdfde20e05d8450a6/jojowigu.pdfIn PDF document text
    • http://hoteldanang.vn/uploads/images/files/56162405330.pdfIn PDF document text
    • https://europartner2.pl/uploads/21490429000.pdfIn PDF document text
    • https://diversifiedhumansolutions.com/wp-content/plugins/super-forms/uploads/php/files/e6b83ff393ec0274b900013b39d91ca0/8699176512.pdfIn PDF document text
    • https://concertwristband.com/resimler/files/78997369187.pdfIn PDF document text
    • https://infrastone.com/userfiles/files/11149607723.pdfIn PDF document text
    • http://staropolski.net/Upload/file/nabavilulazefukupiguv.pdfIn PDF document text
    • https://avgdesign.com/userfiles/file/66360171009.pdfIn PDF document text
    • https://webgirls-studio.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a7ff3c5ba55---47765362479.pdfIn PDF document text
    • http://pm-property.pl/userfiles/file/99477038081.pdfIn PDF document text
    • http://simonide.org/userfiles/file/lamugedo.pdfIn PDF document text
    • http://indiebookoftheday.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bd95cad2dd1---zapunebugivulofikeko.pdfIn PDF document text
    • https://memoservicesrl.it/file/gajafolokafegumugowozijel.pdfIn PDF document text
    • http://share-world.tw/userfiles/file/26804350670.pdfIn PDF document text
    • https://study4student.com/cache/fck_files/file/44105801140.pdfIn PDF document text
    • https://donnasalon.ru/wp-content/plugins/super-forms/uploads/php/files/7aa5c50326d77ffcd4dbcfb8bdad95b2/98498716156.pdfIn PDF document text
    • https://electrabicycles.pl/app/webroot/uploads/file/16271585962983.pdfIn PDF document text
    • http://dangkyidol.com/wp-content/plugins/super-forms/uploads/php/files/vvhrth9360d8d0tq0h1a82tcuk/10367371363.pdfIn PDF document text
    • http://hanarotalk.com/userfiles/file///63453340401.pdfIn PDF document text
    • https://salvamontbihor.ro/app/webroot/files/userfiles/files/3646723236.pdfIn PDF document text
    • https://www.axelendinggroup.com/wp-content/plugins/super-forms/uploads/php/files/6b14f394fceb0409c4091fbb2dd22afe/vufubeka.pdfIn PDF document text
    • https://autosofortkauf.ch/wp-content/plugins/super-forms/uploads/php/files/t1ciiejloksh5ki9901k2ngs5m/rojegotopisavuk.pdfIn PDF document text
    • http://www.morenoroofing.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c06dd70ddf1---10326174954.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/PmAiG5ZyT-k/uplcv?utm_term=cuentos+cortos+infantiles+de+reflexionPDF 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 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off000128b7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x128B7 10700 bytes
SHA-256: 00b4c276297fb388fff7a78ddfa8834dd311497ac4e2a9dc539a6fbfb011d135
font_01_sfnt_off00014178.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14178 19688 bytes
SHA-256: 7a1cfe593466154d974a5f5ecb8c689f0eb808b88b3d62643b2ffed04d1d4484
font_02_sfnt_off0001742e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1742E 17544 bytes
SHA-256: f8e2f987e1d19590e7633c91a51566b61d787cbf11f80357e1879ac65b3bb161
font_03_sfnt_off00018ec6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x18EC6 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1

Open this report in the interactive analyzer, or submit your own file for analysis.