Introduction
A dangerous zero-day vulnerability has been discovered in Internet Explorer that is currently being exploited by hackers to spread malware. This critical bug needs immediate attention as it puts millions of Internet Explorer users at risk of having their systems compromised.
What is a Zero-Day Vulnerability?
A zero-day vulnerability, also known as 0day vulnerability, is a software security flaw that is unknown to the party responsible for patching the flaw. Hackers can exploit the vulnerability to adversely affect computer programs, data, additional computers or a network.
Zero-day exploits are a severe threat because they give no time for developers to address and patch the flaw before large-scale attacks begin. As the flaw remains unknown, traditional security measures are ineffective in blocking the exploit.
Details of the Internet Explorer Zero-Day Bug
Researchers have found that the zero-day vulnerability exists in the way Internet Explorer handles MHTML files. MHTML, which stands for MIME HTML, is a web page archive format used to combine resources like images and documents within an HTML document.
The flaw allows an attacker to corrupt the memory and execute arbitrary code when a specifically crafted MHTML file is opened by the browser. The attacker could then install programs, modify data or create new accounts with full user rights.
Microsoft has confirmed the vulnerability, which affects Internet Explorer versions 9, 10 and 11 on Windows systems including Windows 7, 8/8.1 and even Windows 10.
Real-World Attacks Exploiting the Bug
Cybersecurity firm FireEye reported that this IE zero-day bug is being actively exploited in the wild as part of targeted attacks. The attacks install a backdoor Trojan to compromised systems, allowing hackers full remote access and control.
Specific targets appear to be aerospace and energy sector firms in the U.S. and Asia. However, all IE users are potentially vulnerable and at risk until Microsoft releases a patch.
Protecting Yourself From the Zero-Day Threat
As no official patch is available yet, users need to take steps to minimize exposure. The most effective way is to stop using Internet Explorer and switch to an alternative browser like Firefox or Chrome that is not affected.
For those who need to use IE, some mitigations include:
- Disabling Internet Explorer in the meantime if possible
- Avoiding opening MHTML files from untrusted sources
- Using the Microsoft EMET tool to apply protection
- Running up-to-date antivirus software from a reputed vendor
Enterprises should block MHTML attachments at mail gateways and disable Internet Explorer where feasible. Applying security patches and restricting admin rights can also limit damage.
When Can We Expect a Fix From Microsoft?
Microsoft has said they are working on an official patch and will release it with the next Patch Tuesday security updates on April 14.
Until the patch is tested and installed on systems, this IE bug will remain a critical zero-day vulnerability putting millions of users in jeopardy. Let’s hope Microsoft addresses it promptly before large-scale attacks begin.
Conclusion
The discovery of an actively exploited IE zero-day vulnerability raises serious security concerns. All organizations and individual users relying on Internet Explorer for web browsing should be on high alert. Switching to an alternative browser is highly recommended until an official fix is released and tested. Proactive mitigation steps should also be applied immediately to minimize the risk as much as possible.
