Nov 28, 2022

Know All About Cookie Hijacking and its impact on your brand

The digital ad spend in 2020 was around $385 Bn, globally, and is expected to increase in upcomingyears. The ongoing advancement in digital marketing is luring for attackers to adapt more maliciousways of earning through digital traps.

It might appear that paying commission for every purchase represents a zero-risk strategy, but thethought is ridiculously good to be true.

Fraudsters are employing false methodologies to increase their affiliate commission without considering its consequences. These affiliate traps significantly impact your brand reputation, pump up your advertising cost, and even hamper your customer experience.

One of the scariest affiliate traps is cookie hijacking. A recent study by SANS reveals that over 31% of e-commerce applications are vulnerable to cookie hijacking. Is your online business safe?

In this article, we will describe what cookies are, how fraudsters use cookie hijacking, its impact on online business, and most importantly, the ways to protect your customers from attackers.

What are Cookies?

Cookies refer to small data files generated by the web browser and sent to the webserver. The web browser stores these cookies for the length of the user's session on a particular website.

These cookies allow the site to maintain the visitor's browsing history and make it convenient for a user to revisit a website.

Cyber attackers hijack and manipulate these cookies to deceit the advertisers and in turn, earn commissions.

What is Cookie Hijacking?


Cookie hijacking is the insertion of an affiliate cookie by distributing adware through web browser extensions or software applications (Windows & MAC). This is executed by hijacking the click elements on advertiser's websites.

In this process, the attackers control the entire session of the user on the advertiser's site by modifying the stolen cookies. They can insert affiliate cookies in the customer's journey or the worst-case scenario, make an unauthorized purchase. It leads to a significant loss for the advertiser's marketing budget.

How Does It Work?

When a threat actor plans for cookie hijacking, the foremost requirement is having unauthorized remote access to the cookies. They try to accomplish their intention by hijacking user's web sessions to steal their personal information and get access to their systems.

There can be several ways to introduce the trap. Here are the four most commonly used methods for cookie hijacking:


  • Adware/Malware: Unwanted programs(adware/malware) bundle up with helpful software and find a way into the user's system. Attackers use such malware for the packet sniffing specifically set to penetrate session cookies. The malware induced in the victim's system provides remote access to their machine. The attackers can navigate the local system remotely and access the cookies of their use.
  • Click Hijacking: The fraudsters steer click elements, such as the call to action buttons, a search bar, blank space, or a footer to insert affiliate cookies. Whenever the customer clicks on any hijacked component on the advertiser domain and completes a purchase, the affiliate earns a commission for the sale. The result turns out favorable to attackers, the affiliates earn a commission without driving legitimate traffic to the advertiser's website.
  • Session Fixation: During a session fixation attack, fraudsters launch a fixed session in the user's browser. Hence, the user is trapped without even logging in. A web-based session fixation can be established in multiple ways, mostly through session identifiers accepted from malicious posts or URLs. The most conventional way adapted by hackers is sending an email (that appears coming from a trusted entity). As the user opens the email and follows the link, the attackers can tweak their web server session. Without more ado, they can easily redirect them to a fixed valid session that can fulfill their purpose.
  • Cross-Site Scripting: Cross-Site scripting discusses the injection of malicious software through a running code. These scripts appear to be the browser's side script. Affiliates use cross-site scripting to target buyers and customers. The buyers and customers execute the script believing it stems from a credible source. Once the users access these scripts, the affiliates can access their session details, cookies, and other sensitive information. Once the affiliates are successful in customer journey hijacking, they modify the hijacked cookies and add affiliate cookies to mislead the advertiser.


What Is the Purpose of Cookie Hijacking?

Cookie hijacking exploits the web session control mechanism, usually managed by cookies. The process forges a valid cookie to steal the user data, bypass the security, or both.

The primary purpose for affiliate frauds is to practice cookie hijacking:


  • Auto-redirection: Users are redirected to different product pages by cookie hijacking. It can be on another product page or a similar page, as per the intent of the hijacker.
    For example, the user visits to buy groceries, but affiliates trap them by hijacking the search bar and drops an affiliate cookie as the user clicks on the search icon.
  • Unexpected results: Click hijacking might lead to a result that entirely mismatches the customer's query. For example, the buyer searches for bags but receives results for clothing or shoes.
    This ultimately hampers the brand reputation, brand image, loss of valued clientele, and eventually the brand revenue.
    For creating affiliate traps, the attackers employ various methods to disrupt the buyer's flow. They smartly modify the native cookie with the affiliate cookie to grab a false commission.


Impact of Cookie Hijacking:

Cookie hijacking is a result of the limitation of the stateless HTTP protocol. The trap has presently become a significant threat for the affiliate market, Global digital ad spends, user privacy, and online business.

The three vital consequences of the ongoing affiliate trap are described below.


  • Advertiser Revenue: According to a study by the University of Baltimore, the total ad fraud in 2020 was 23 billion dollars. Out of which, 1.4 billion dollars was due to affiliate marketing frauds. Cookie hijacking is one of the prominent ways used by fraudsters to steal inappropriate commissions.
    Without acquiring any new audience for the brand, the affiliates seek the commissions and thus impact the overall advertiser's marketing budget.
  • Brand Reputation: The threat actors often redirect the users multiple times to inject cookies into their system. The adware affects the user's system and slows down the browsing experience of the customers. This hampers the reputation of the renowned brand and disregards the trust of their customer base.
  • Poor Customer Experience: The attackers regulate the session/cookies of a customer remotely. Once they hijack the session, they can perform all the actions like that of an authorized user. It can be accessing the personal details for theft, amending the session of the customer journey, or not allowing the user to perform desired actions.
    All of the above can lead to poor customer experience and if the user observes the malicious activities while on an advertiser's site, they might lose their trust in brands.


How To Protect Your Brand from Cookie Hijacking?

Identifying cookie hijacking when it's active is highly challenging. Even the updated versions of antivirus and malware can only detect, once the session is modified or the damage is done.

Well, that does not mean there is no way you can protect your brand and its reputation. Virus Positive Technologies and its top-notch team of engineers have identified several ways to deal with cookie hijacking and all other types of affiliate traps.

Contact us at to know more about our brand compliance monitoring tools and customized solutions to break through the Affiliate Traps and safeguard your brand reputation.

Gaurav Sethi

Gaurav is a passionate people man who has worked on delivering business solutions and unlocking business value for a wide array of clients across different industry verticals and across different geographies. He has been an esteemed speaker at various Ad tech events for many years. With his pedigree rich in technology and business management, he has been an entrepreneur for over 15 years.