Symantec researchers spotted a new
Symantec has identified a total of 11 organizations hit by the threat actor, most of them are based in Saudi Arabia, for two of them, the attackers gained domain admin-level access.
“A previously undocumented attack group is using both custom and off-the-shelf malware to target IT providers in Saudi Arabia in what appear to be supply chain attacks with the end goal of compromising the IT providers’ customers.” reads the analysis published by Symantec.
In two attacks carried out by the TortoiseShell group, the threat actor infected hundreds of hosts, this is an anomalous behavior that suggests it was searching for specific machines of interest.
The group used both custom malware and off-the-shelf hacking tools for its campaigns, such as the Syskit custom backdoor that was discovered on August 21.
The Syskit is
The malicious code collects machine’s info (i.e. IP address, operating system name and version, and Mac address) and sends them to the C&C is Base64 encoding. The malware supports several commands, such as download other malware and launch PowerShell to unzip a file or run commands in the Command Prompt console.
The group was observed using other publicly available tools, including:
The two info-grabbing malware can collect details about the machine they landed on and “Firefox data of all users of the machine.”
“We also saw Tortoiseshell using other dumping tools and PowerShell backdoors.”
Experts pointed out that the initial infection vector used by
“On at least two victim networks, Tortoiseshell deployed its information gathering tools to the Netlogon folder on a domain controller. This results in the information gathering tools being executed automatically when a client computer logs into the domain.” continues Symantec.
In one of the targeted organizations, Symantec experts observed the presence of Poison Frog, a PowerShell-based backdoor associated in the past with operations carried out by the Iran-linked
However, the presence of Poison Frog is not sufficient to attribute the attacks to OilRIG because the source code of the
“The targeting of IT providers points strongly to these attacks being supply chain attacks, with the likely end goal being to gain access to the networks of some of the IT providers’ customers.” concludes Symantec.
“This provides access to the victims’ networks without having to compromise the networks themselves, which might not be possible if the intended victims have strong security infrastructure, and also reduces the risk of the attack being discovered.”