Open Source Hacking Tool Grows Up

An open source white-hat hacking tool that nation-state hacking teams out of China, Iran, and Russia have at times employed to avoid detection has been updated with new features that allow attacks to persist and spread more efficiently.

Sean Dillon, creator of the so-called Koadic tool that works like a remote access Trojan (RAT), says the software he first released two years ago at DEF CON can now extract information and intelligence about a targeted Windows environment, more efficiently scrape user credentials, and more easily spread around a network. "It's much more efficient now. It can be used to compromise entire networks in a matter of minutes," says Dillon, who plans to show off Koadic's new features next month at the Black Hat USA Arsenal in Las Vegas.

Koadic is basically a RAT based on VBScript and JScript that uses Windows executables such a PowerShell rather than malware, so it mimics a growing trend of sophisticated attackers employing legitimate tools instead of writing or burning their own exploits. The trend, known as "living off the land," also allows attackers to remain under the radar as they run internal Windows tools like PowerShell to hack their way through networks.

Koadic uses built-in Windows executables and most recently added a Windows Management Interface and SysAdmin to its quiver. "These are binaries that are shipped by default with all versions of Windows," Dillon notes, and they are signed by Microsoft so they can slip past most whitelisting applications. The original version of Koadic targeted a single machine and had little ability to move laterally to other machines.

"We now have several different ways to poke into the system, and when a computer is back up from a restart" the attack will continue, he notes.

Among some of the newer features: UAC (user account control) bypasses, automated file-discovery, and credential storage that converts Mimikatz outputs into a searchable form.

Nation-state groups, such as China's Stone Panda, Iran's MuddyWater, and Russia's Fancy Bear, all have been spotted using Koadic in their hacking campaigns. "In the past year or two, APT groups have been using open source tools in order to hide out," Dillon says. "If they write custom malware, the attack could be attributed to them. ... If they use something open source, it's hard to see who is attacking an organization."

But Dillon's intent for the tool is to help professional penetration testers find holes before the bad guys do. Still, Koadic today continues to easily bypass most endpoint security tools: "Every time [the vendors] come up with a detection for it, we come up with another evasion," he says. Sometimes it's only a matter of changing a comma or a word in the string, and it breaks the anti-malware vendor's detection signature, he notes.

That underscores the need for better behavioral detection methods for defenses, he adds.

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