Once the data is intercepted and exfiltrated, the attackers display an error message and the customer is redirected to the real payment page. Customers probably just enter their details again and it takes several days/weeks before they notice they’ve been charged twice.
A rare attack on multiple ecommerce platforms
It is remarkable that so many different platforms are compromised in the same campaign. Typically, criminals exploit a flaw in a single platform. Attackers may have breached a shared component, a piece of software or a service that is used by all affected merchants over the different ecommerce platforms.
Another curious technique is that this skimmer uses programmatically generated exfiltration domains. It keeps a counter and uses base64 encoding to produce a new domainname:
This will lead to, for example, these exfiltration domains. The first one was registered on August 31st.
zg9tywlubmftzw5ldza.com zg9tywlubmftzw5ldze.com zg9tywlubmftzw5ldzu.com zg9tywlubmftzw5ldzq.com zg9tywlubmftzw5ldzm.com zg9tywlubmftzw5ldzy.com zg9tywlubmftzw5ldzi.com zg9tywlubmftzw5ldzg.com zg9tywlubmftzw5ldzk.com zg9tywlubmftzw5ldzez.com zg9tywlubmftzw5ldzex.com zg9tywlubmftzw5ldzew.com zg9tywlubmftzw5ldzey.com zg9tywlubmftzw5ldze0.com zg9tywlubmftzw5ldze1.com
Here is an example of how the raw malware is hidden in the ecommerce websites:
SaaS ecommerce platforms and security
This campaign shows that platforms are no boundary to the profitable fraud of web skimming or formjacking. Wherever customers enter their payment details, they are at risk. Merchants should implement measures to actively counter this.
Please contact Sansec if you think an attacker has added a fake payment form to your ecommerce website.