A couple of years ago I had problems with the Safety Module of Banco do Brasil and did some research on the subject. I warn you that I am not an expert in security, nor do I have knowledge about the internal functioning of these software.
What are Security Modules
Each bank has a solution, so I will limit my response to Banco do Brasil.
According to own bank reference:
The Security Module is a protection system that, during the execution of electronic transactions, acts as a shield of your computer against attacks of malicious programs on the Internet.
In theory, a security module is like a mini antivirus and anti-spyware that would protect the bank from fraud.
The supplier
According to some sources (see this) the company that provides the technology and software for both BB and Box is the Gas Tecnologia.
The product
The website of this company announces the anti-fraud solution for e-banking as "a solution that structures an armored and specialized virtual environment, with the necessary requirements for financial transactions through the Internet channel".
Some of the features shown are:
Strong device identification and authentication system
At least at BB, you need to register each computer from where you want to access the bank’s website.
However, I usually use a virtual machine to access my account. I once made a copy of this image to another computer and the access stopped working. Analyzing the incident, I realized that I had to configure the network card of the new virtual machine with the same MAC Address as the previous VM.
Analysis by watering model of user and end-point behavior in the Web channel and in multiple channels (ATM, URA, Mobile Banking)
You may be able to check if someone is actually clicking on the buttons or if there is a "robot" accessing the bank.
Differentiated service based on Knowledge Systematized through tools and processes for risk analysis and fraud detection
Probably the software tries to identify strange user behavior or processes on the computer.
The solution has direct action on the channel deficiencies and vulnerabilities that enable fraud and violation of privacy on the account holder
The tool should try to treat known vulnerabilities in the operating system or browsers, for example.
Generation of audit trail
The system must log the user’s activities on the bank’s website. This would make it possible to identify the perpetrator of fraud online.
Able to prevent mass attacks on web services
The tool should prevent quick access to services, avoiding denial of service attacks.
Controversy
Several users denounce this module as a type of virus or malware.
In particular, I had a similar impression. A few years ago my computer presented periods of instability in Internet access and slowness (99% CPU) after the installation of the BB Security Module. This was one of the reasons I decided to use Vms.
After installing the module on a computer, the user cannot close it or remove it. The behavior is similar to those malware placing multiple processes. You close one of the processes and it reopens automatically.
It’s more a great marketing than a real solution. I have done several tests with cloning of MAC, copy of data "hidden" in strategic places, and make sure that it is relatively simple to circumvent these systems (so much so that there is a serious bank that does not install anything for netbanking, and goes well). On the other hand, the headache this gives to ordinary customers is a disgrace. The solution of modules is usually delayed compared to browsers, and often wide services and tasks running unnecessarily on customers, plus conflicts with applications already installed in some cases.
– Bacco