A DigitalPoint Forums member found a bunch of modifications to his site, including AdSense code: the code on the page was not his.
This isn't the first time this happened and it's probably not the last. Some precautions:
- Check your AdSense earnings; if they drop, there may be a problem. Then, check that the AdSense ID is correct on your website.
- Contact your hosting company to see if you can trace who hacked the site. It's worth a try.
- Contact Google with the new AdSense code and inform them that this is not your code. The code may either be someone else's or the hacker's himself: Google will make a decision about whether or not to disable the account.
There are no guarantees that anything will be done but you can always report violations to Google AdSense Help.
Forum discussion continues at DigitalPoint Forums.