Exploit kits, or exploits, are designed to gain access to a system and then install malicious code.
The latest versions of the Microsoft software have been found to be able to run as root.
This is not the first time the exploits have been linked to the same person, however.
The Russian hacker group Pawn Storm recently posted an exploit kit on the dark web that was also claimed to have been used by the Syrian government.
The hackers had also posted a similar kit on Reddit.
But Microsoft has never officially acknowledged the existence of a kit that it released in 2015, and a spokesperson for the company declined to comment on the reports.
The company has previously said that it has “taken all appropriate actions to prevent and stop exploits” from being used by any country.
A spokesperson for Microsoft told Al Jazeera that Microsoft has taken “significant steps” to stop exploits being used to target customers.
“The recent reports that a Microsoft exploit kit was being used in Syria are completely false,” the spokesperson said.
“We have taken all appropriate steps to prevent exploits being released by any state.”
But the spokesperson declined to address the validity of the Russian claims.
“This is just the latest of several attempts by foreign governments to exploit vulnerabilities in our products and systems,” said the spokesperson.
Microsoft has been working to secure Windows, and its systems have been patched with more than 10,000 security patches since the beginning of the year.
The Windows Defender Anti-Virus toolkit has also been updated with a new version that has been installed by default.
“Microsoft is working with industry partners to deploy a patch as soon as possible, to reduce the likelihood that new vulnerabilities are found in these products,” the company said.
Microsoft’s Security Essentials program also now offers free updates for Windows and Microsoft Office software.
“For many years, Microsoft has supported Microsoft Office and Windows by providing free updates to users for free, and it continues to do so for Office and other Windows-based products,” a spokesperson told Aljazeera.