How Pirated Themes Harm your site?
Nulled or pirated themes may contain malicious codes. Some part of coding in Encrypted form, which you can not understand. Such coding may cause serious issues to you.
1. Hidden Iframes : The iframes are used to embed another document within your web pages. Many themes have forced footers. If you remove it, your theme won’t work. These footers can be managed remotely. Immediately disable such themes, if you are using.
2. Hacking : Such themes can give your WordPress details to the hackers. A common symptom seen is unwanted users. Even if you haven’t enabled user registration, you see some users in WordPress admin. These users may have admin access to your blog. This is called back door access. These users may manipulate your database, insert any code injection into your blog or simply get your database information.
3. Malware : You should (at least) scan the .zip file you have downloaded. It may contain malware or spyware. If you directly upload the .zip file, your blog or site might be marked as malicious. Web hosts immediately suspend such sites. Search engines may de-index your site permanently.
4. Cloaking : Cloaking is presenting different content to Human users and Search bots. For example, let’s say you run a blog about fruits. You have optimized it well for SEO. But if your theme is showing something else to search bots, may be p*rn, you will never rank for your targeted keywords. Cloaking is very bad and may lead to getting your site de-indexed forever. Many themes are found to be having cloaking code in them. Such sites show different content to search engines. Hence they can never rank well.
5. Important Updates : Core WordPress, plugins and themes keep on updating to address important functional, compatibility and security issues. If you are using a pirated theme, you do not get these updates. So, obviously, you get at a risk point. Your theme may or may not work properly after WordPress update.
Piracy is Bad!
As you are using pirated theme, you are not on the safe side. The theme company can take legal action against you. Genuine web hosts do not support nulled content. They can disable or suspend your blog permanently.
How to determine malicious code in themes?
Up till now we talked about pirated themes. But many free themes may also harm your blog. So, it is always recommended to download themes from trusted sources.