Wp-vcd is hiding itself in pirated Wordpress themes. The pirated themes can be found on several websites via the Google search. When installed, Wp-vcd will compromise the systems of webmasters who are not willing to pay for the work of a developer.
Initially the backdoor was found by downloading the theme ExProduct from the site downloadfreethemes. This website is hosting a lot of pirated Wordpress themes. At the time of writing, the site was hosting 32.200 themes.
https://file.gdatasoftware.com/web/en/documents/whitepaper/G_Data_Whitepaper_Analysis_Wp_vcd.pdf
ref - https://www.reddit.com/r/ReverseEngineering/comments/82m5cm/a_further_look_into_the_wpvcd_wordpress_backdoor/
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