Vulnerabilities in Adobe Flash Player are discovered with such regularity that news of another raises few eyebrows, but the latest critical vulnerability – discovered in Adobe Flash Player 22.214.171.124 and earlier versions – is a cause for concern. It is already being exploited by hackers and is being used to infect users with ransomware.
Any device that is running Adobe Flash Player 126.96.36.199 (or earlier) is at risk of the vulnerability being exploited and malicious file-encrypting software being installed. The latest vulnerability can be used to attack Windows, Macs, Linux systems and Chromebooks, according to ProofPoint, although Adobe reports that the vulnerability only affects Windows 10 and earlier versions running the vulnerable versions.
Flash vulnerabilities are usually exploited by visiting malicious websites or webpages that have been compromised and infected with exploit kits. Those exploit kits probe for a range of weaknesses, such vulnerabilities in Adobe Flash Player, and exploit them to download malware or ransomware to the user’s device.
These drive-by attacks occur without users’ knowledge, as the downloaded file is not displayed in the browser and is not saved to the download folder. It is also difficult to determine whether a website has been compromised or is malicious in nature without software solutions that analyze the website content.
Vulnerabilities in Adobe Flash Player Exploited to Deliver Cerber and Locky Ransomware
The latest attack uses the Magnitude exploit kit. The fact that it is Magnitude suggests the latest ransomware attacks are the work of an individual cybercriminal gang. That gang has acted quickly to include the latest Flash vulnerability into Magnitude.
According to Trend Micro, the vulnerability is being used to deliver Locky ransomware – the malicious file-encrypting software that has been used to attack hospitals in the United States in recent weeks. Locky was reportedly the ransomware used in the attack on Hollywood Presbyterian Medical Center in February. That infection cost the healthcare organization $17,000 to remove, not to mention the cost of attempting to remove the infection and restore backup files prior to the ransom being paid.
ProofPoint suggests the vulnerability is being used to deliver Cerber ransomware. Cerber is a new ransomware that has was released in the past month. It can be used to encrypt files on all Windows versions, although not those in Russian.
Cerber and Locky are being downloaded via malicious websites, although these are typically not visited by the vast majority of Internet users. In order to get traffic to these sites the attackers are using spam email containing malicious attachments.
In contrast to many malicious spam emails that install malware using executable files and zip files, the attackers are using Word documents containing malicious macros. The macros do not download the ransomware directly, instead they direct the victim, via a number of redirects, to a malicious site where the drive-by download takes place.
The vulnerability, named as CVE-2016-1019, will crash Adobe Flash when it is exploited. Adobe reports that the vulnerability exists in 188.8.131.52. Trend Micro says the exploit will not work on versions 184.108.40.206 and 220.127.116.11, only on Flash 18.104.22.1686 and earlier versions due to mitigations put in place by Adobe.
ProofPoint’s Ryan Kalember said that the exploit has been engineered to only work on earlier versions of Flash and that attacks have been degraded to evade detection. All versions of Flash could potentially be used for the attack should the criminals behind the Magnitude exploit kit so wish.
Of course, this is just one of many vulnerabilities in Adobe Flash Player that can be exploited and used to deliver ransomware or other forms of malware. To prevent attacks, sysadmins should ensure that all devices are updated to the latest version of the software. Adobe said it was releasing a security update to address the vulnerability on April 7, 2016.
Vulnerabilities in Adobe Flash Player are addressed with updates, although there are two software solutions that can help to protect users from attack. Anti-spam solutions such as SpamTitan can be used to prevent spam email from being delivered, reducing the risk of end users opening Word documents infected with malicious macros.
WebTitan products tackle these attacks by blocking malicious websites, preventing users from visiting sites where drive-by downloads take place. There is usually a wait while vulnerabilities in Adobe Flash Player are addressed, and these two solutions can help keep devices malware free until updates are applied.