The Iran-affiliated threat actor tracked as MuddyWater (aka Mango Sandstorm or TA450) has been linked to a new phishing campaign in March 2024 that aims to deliver a legitimate Remote Monitoring and Management (RMM) solution called Atera.
The activity, which took place from March 7 through the week of March 11, targeted Israeli entities spanning global manufacturing, technology, and information security sectors, Proofpoint said.
"TA450 sent emails with PDF attachments that contained malicious links," the enterprise security firm said. "While this method is not foreign to TA450, the threat actor has more recently relied on including malicious links directly in email message bodies instead of adding in this extra step."
MuddyWater has been attributed to attacks directed against Israeli organizations since late October 2023, with prior findings from Deep Instinct uncovering the threat actor's use of another remote administration tool from N-able.
This is not the first time the adversary – assessed to be affiliated with Iran's Ministry of Intelligence and Security (MOIS) – has come under the spotlight for its reliance on legitimate remote desktop software to meet its strategic goals. Similar phishing campaigns have led to the deployment of ScreenConnect, RemoteUtilities, Syncro, and SimpleHelp in the past.
The latest attack chains involve MuddyWater embedding links to files hosted on file-sharing sites such as Egnyte, Onehub, Sync, and TeraBox. Some of the pay-themed phishing messages are said to have been sent from a likely compromised email account associated with the "co.il" (Israel) domain.
In the next stage, clicking on the link present within the PDF lure document leads to the retrieval of a ZIP archive containing an MSI installer file that ultimately installs the Atera Agent on the compromised system. MuddyWater's use of Atera Agent dates back to July 2022.
The shift in MuddyWater's tactics comes as an Iranian hacktivist group dubbed Lord Nemesis has targeted the Israeli academic sector by breaching a software services provider named Rashim Software in what's case of a software supply chain attack.
"Lord Nemesis allegedly used the credentials obtained from the Rashim breach to infiltrate several of the company's clients, including numerous academic institutes," Op Innovate said. "The group claims to have obtained sensitive information during the breach, which they may use for further attacks or to exert pressure on the affected organizations."
Lord Nemesis is believed to have used the unauthorized access it gained to Rashim's infrastructure by hijacking the admin account and leveraging the company's inadequate multi-factor authentication (MFA) protections to harvest personal data of interest.
It also sent email messages to over 200 of its customers on March 4, 2024, four months after the initial breach took place, detailing the extent of the incident. The exact method by which the threat actor gained access to Rashim's systems was not disclosed.
"The incident highlights the significant risks posed by third-party vendors and partners (supply chain attack)," security researcher Roy Golombick said. "This attack highlights the growing threat of nation-state actors targeting smaller, resource-limited companies as a means to further their geo-political agendas."
"By successfully compromising Rashim's admin account, the Lord Nemesis group effectively circumvented the security measures put in place by numerous organizations, granting themselves elevated privileges and unrestricted access to sensitive systems and data."
