spamAmongst Internet tools, one of the most reviled amongst white hat SEO experts (and revered amongst Black Hat SEO experts) is XRumer. In essence, XRumer is a software program which is designed to help you get tens of thousands of instant backlinks from all over the Internet. The thing is, virtually every possible use of XRumer is going to be for the purpose of creating spam.
Now, that doesn’t necessarily mean that all your spam links are so evil. In some cases, they can be pretty innocuous, though as a general rule, it’s a bit limited and very difficult to actually create something worthwhile by using the program. Here are the two things that XRumer can do for you:

Profile Backlinks

XRumer will create a profile for you on various forums all over the Internet and include inside of that profile a backlink to your website which includes the anchor text of your choice. This does tend to create backlinks for you, some of which will be indexed and get you at least some rankings for your trouble.
The problem with this approach however is that it is still spam and forum profile backlinks tend to be extremely low hanging fruit (unlike forum posts, profiles are much more rarely deleted by moderators). Google knows this and as such, they tend to treat such backlinks as being about the most worthless of backlinks.

Forum Posts

The second part of using XRumer is that you can create forum posts on thousands of forums all over the Internet. The posts can be created in hundreds of thousands of forums and according to most estimates I’ve seen, around 30% of those forum posts will be kept online.
You can even spin the forum posts so that they appear somewhat unique, though most people don’t tend to bother doing so, instead posting something like “I’m brand new here, hi.” Some people also put up pure spam links, including one person who periodically spams the Warrior Forum with porn links.
The thing is, these kinds of posts are the ones that annoy people the most and they are also much more likely to get your website de-indexed for using black hat SEO tactics.

Bottom Line

To be honest, I can’t really see a reason to make use of XRumer. You can use it to create profile backlinks which will stick and which aren’t likely to get you de-indexed, but frankly, such links are so worthless that I’m not sure they’re worth the cost of XRumer.
For the other side of the program, creating forum posts, XRumer is definitely not worth bothering with since such posts may get you deindexed from Google. Bottom line, I just can’t see a reason to bother with it.