I went ahead and added the widget back into my clients sidebar so you can have a look at the source code – bottom of the sidebar:
https://www.mcpactions.com/blog/
Other plugins are basic – SEO, Lightbox, ExecPHP, Google analytics, sitemap, there are about 42 active plugins (well, 43 I guess if yours showed up in the plugins panel). Upgraded to the most recent version of WP and it disappeared.
The malware warnings were delivered by WOT (web of trust add on/firefox) for me, not sure about the other person.
She is really hoping that you have a solution for why it would not appear. Is there something in the plugin that requires something particular in theme functions for the widgets?