Common negative SEO techniques include site intrusion, content manipulation, and link spamming. In order to protect your website against Negative SEO, you need to understand the most common ways and what exactly they are doing.
Site intrusion occurs when your web site is hacked. Hackers will install malware or malicious code into your source code to negatively impact your SEO efforts. As you can imagine Google has software and algorithms that pick up on this stuff fast and you will get heavily impacted in a way that you don’t want. You need to make sure your website always has the up-to-date security patches and monitor your code looking for weird changes that you don’t remember. Sometimes even having third party files on your website can allow a hacker into your site.
Content can be very easily duplicated and unless it’s a blatant copy of your text it’s hard to have it enforced as being your original work. When this happens Google will assign a higher rank to one of the text and the other will get a negative impact because Google determines only one to be original and the others are duplicates. Most cases Google will assign the text who was wrote first the higher rank, but that is not always true.
Another similar method is to take your content and post it all over the web. When this happens their goal is to have a higher chance of your page being the one to get penalized.
You should be checking for duplicate content on a regular basis ensuring that people are not copying what you are posting and trying to take credit along with trying to negatively impact your website. A good website to use is copyscape.com. You put in the URL you want checked and it will scan the web for similar content. If you find content that you feel is duplicated it is suggested that you contact the website owner/manager and request for it to be changed or removed. If they don’t comply with that you can file a DMCA complaint. If you have found a lot of websites copying your content it might be easier for you to change your content. You shouldn’t have to, but sometimes you have to be bigger person and in the end it’s easier for you.
Another great way to help avoid duplicate content is to have dynamic content that changes regularly. This doesn’t mean daily or hourly, but having content that changes every few months isn’t a bad idea. It will make it harder for people to duplicate your content.
With the new Penguin update that Google did their algorithm now detects websites that have “too many low quality links”. This isn’t as big of an issue because it would take hundreds of low quality links to skew the ratio enough for Google to apply some negative impact to your website. This is still a possibility, but the task isn’t as easy and the others. Plus, Google doesn’t scan in live time it’s only “every so often”…however often that is gets left up to Google.