Top financial regulators in the U.S. warn banking institutions that the Shellshock bug could expose them to fraud, Reuters reported.

According to security experts, Shellshock is a new online threat that targets the commonly used operating system known as Bash.

It is considered more dangerous than April of this year's Heartbleed bug because the Shellshock can allow the attacker to take full control of the affected device to run commands or install various programs.

Heartbleed, on the other hand, only exposed sensitive data and passwords, according to JC Online.

As a security measure, the Federal Financial Institutions Examinations Council (FFIEC) urges banks to install patches and fix their software to prevent the Shellshock from infecting their networks.

"The pervasive use of Bash and the potential for this vulnerability to be automated presents a material risk," the FFIEC said.

The FFIEC highly encourages banking institutions and other companies to identify Bash-based systems and update them.

Aside from banks, Apple and software developer Oracle announced that they are working on patches to protect their devices and services from the Shellshock bug. These can be downloaded by the public once they are ready for release, The Sunday Morning Herald reported.

Mac users are susceptible to the bug since their devices run on the Mac OS X, which is packaged with the Bash and is based on the Unix operating system.

"We are working to quickly provide a software update for our advanced UNIX users," Apple said in a statement.

iPads and iPhones, on the other hand, which use Apple's iOS, seem to be safe from the bug.  

As for Oracle, the tech company announced last week that more than 30 of its devices are at risk of being affected by Shellshock. These include the company's Exadata computer systems.

According to the company, the patches it is working on will only be available for the Oracle Linux and Solaris operating systems.