Malvertising refers to cyber criminal attacks which use online advertising channels to infiltrate malicious code and malware into the user computers. Accessing these codes can harm user’s computer even to the extent of damaging the data files or stealing personal information.
There are different ways by which attackers can spread Malware. The malicious code can be placed in the ad itself thus making the ad infected or clicking the ad could redirect the users to the site which is infected with malware. Usually, what advertiser does is , in the beginning, they serve clean ads which does not contain malware and once they start getting the major traffic they put a malicious code behind those ads, accessing which harms the visitor’s computer with malware.
Publishers who accept the ads directly from the advertisers and publish them on their sites needs to be very careful . If they publish an infected ad it’s a risk for their sites visitors and also for their own reputation. So, once an ad is accepted , the publisher should run some checks and scans to make sure that the ad is infection free.
Generally, when the ads are submitted to the network , they go through the scans to ensure that they are clean and not contain any infected code. But , these scans can never be perfect.
For e.g. accessing lot of sites, shows pop up ads on it , showing attractive offers or saying that you have won a prize money. Most of those are the attempt by advertisers to spread malware.
ONLINE TRUST ALLIANCE:
OTA (online trust alliance) provides some guidelines which can be followed by both publishers and advertisers to evaluate the integrity of the data used in an advertisement. This evaluation can help in protecting the users from accessing the infected data.
Below are few guidelines provided by OTA , following these can be of great help in preventing against malware attacks.
Ad Serving Domain Risk Factors:
- How long it’s been registered?
- How active is the domain?
- Has the domain been recently transferred to or from a 3rd party?
Ad Tag Risk Factors:
- Does the tag use a flash code?
- Does clicking on tag gives warning message?
Corporate /Website Risk Factors:
- How does the site look? It should not look unprofessional!
- Does the site have obvious errors?
- Does the site has legal SSL Certificate and Expiration of Certificate?
Individual Risk Factors:
- Check for the identity of the contact.
- Does the email address correspond to corporate site?
- Does the reply email address bounce?
- Check their reputation with other well known and trusted the service provider.
- How stable are they when it comes to working with a service provider. Do they frequently change service providers and ad servers?
Types of Malware attacks (Malvertising):
- Banners with malicious code.
- Third party ads and applications on webpage.
- Pop-Up ads.
- Hidden iframes on a webpage.
Some Preventive Measures (Malvertising):
- Don’t blindly trust the advertiser.
- Check for the reputation of the advertiser in the market.
- Use latest versions of browsers and software which could have additional security features. E.g. Use the latest version of Internet Explorer.
- Use anti-virus software capable enough of trapping malicious codes.