What is googletagmanager.eu ?
Often found on online stores,
googletagmanager.eu is a common digital skimmer (also known as Magecart) that was first detected on April 3rd, 2020. So far, Sansec has discovered this malware on 213 different victim stores. The most common attacked platform is Magento 1.
A typical sample of the malware in the wild can be observed when selecting "view page source" in your browser. It looks like this:
How does it work?
The googletagmanager.eu skimmer is loaded on the checkout page of a typical store. It lives in the browser of an unsuspecting online customer. Whenever he or she enters her payment information, the private data is siphoned off to an offshore server. Usually, this data is then sold on the dark web within 2-10 weeks.
How to clean it?
The malware can be easily removed. It is usually hidden in a database field, such as core_config_data, cms_blocks or cms_pages. Sometimes the malware is appended to a specific .js code file. However just cleaning the malware is not enough: you need to discover the root cause of this malware, otherwise you will soon find the same malware back in your store.