WordPress plugins are not 100% safe, your should check these plugins before your installing theme.
If you are a WordPress user you can generate sitemap very easily with WordPress Plugins. There are many sitemap plugins on WordPress can create XML sitemap, yoast is one of the famous sitemap plugin on WordPress.
Except using plugins, you have else method to create sitemap that using the sitemap tool.
What is SitemapHub
Using a crawler to generate your sitemap is pointless. If the sitemap crawler can crawl your site, so can Googlebot.
SitemapHub’s one of features is supports pagination. If your page had next page link and had a
Paging CSS Path value, SitemapHub’s bot will auto crawl the next page until end.
If your site layout structure had changed, you might be change your CSS Path, it will just take up one minute.
Once you finished create a new sitemap, the next step is submit to Google Search Control and Bing WebMaster Tool. See How to submit your sitemap to Google and Bing.