Targeting Snowflake Customer Instances for Extortion and Data Theft, UNC5537
Overview. Mandiant has discovered a threat campaign that targets Snowflake client database instances with the goal of extortion and data theft. This campaign has been discovered through Google incident response engagements and threat intelligence collections. The multi-Cloud data warehousing software Snowflake can store and analyze massive amounts of structured and unstructured data.
Mandiant is tracking UNC5537, a financially motivated threat actor that stole several Snowflake customer details. UNC5537 is using stolen customer credentials to methodically compromise Snowflake client instances, post victim data for sale on cybercrime forums, and attempt to blackmail many of the victims.
Snowflake instance
According to Mandiant’s analysis, there is no proof that a breach in Snowflake’s enterprise environment led to unauthorized access to consumer accounts. Rather, Mandiant was able to link all of the campaign-related incidents to hacked client credentials.
Threat intelligence about database records that were later found to have come from a victim’s Snowflake instance was obtained by Mandiant in April 2024. After informing the victim, Mandiant was hired by the victim to look into a possible data theft affecting their Snowflake instance. Mandiant discovered during this investigation that a threat actor had gained access to the company’s Snowflake instance by using credentials that had previously been obtained through info stealer malware.
Using these credentials that were taken, the threat actor gained access to the customer’s Snowflake instance and eventually stole important information. The account did not have multi-factor authentication (MFA) activated at the time of the intrusion.
Following further intelligence that revealed a wider campaign aimed at more Snowflake customer instances, Mandiant notified Snowflake and potential victims via their Victim Notification Programme on May 22, 2024.
Snowflakes
Mandiant and Snowflake have notified about 165 possibly vulnerable organizations thus far. To guarantee the security of their accounts and data, these customers have been in direct contact with Snowflake’s Customer Support. Together with collaborating with pertinent law enforcement organizations, Mandiant and Snowflake have been undertaking a cooperative investigation into this continuing threat campaign. Snowflake released comprehensive detection and hardening guidelines for Snowflake clients on May 30, 2024.
Campaign Synopsis
According to Google Cloud current investigations, UNC5537 used stolen customer credentials to gain access to Snowflake client instances for several different organizations. The main source of these credentials was many info stealer malware campaigns that compromised systems controlled by people other than Snowflake.
As a result, a sizable amount of customer data was exported from the corresponding Snowflake customer instances, giving the threat actor access to the impacted customer accounts. Subsequently, the threat actor started personally extorting several of the victims and is aggressively trying to sell the stolen consumer data on forums frequented by cybercriminals.
Mandiant
Mandiant discovered that most of the login credentials utilized by UNC5537 came from infostealer infections that occurred in the past, some of which were from 2020. Three main causes have contributed to the multiple successful compromises that UNC5537’s threat campaign has produced:
- Since multi-factor authentication was not enabled on the affected accounts, successful authentication just needed a working login and password.
- The credentials found in the output of the infostealer virus were not cycled or updated, and in certain cases, they remained valid years after they were stolen.
- There were no network allow lists set up on the affected Snowflake client instances to restrict access to reliable sources.
Infostealer
Mandiant found that the first infostealer malware penetration happened on contractor computers that were also used for personal purposes, such as downloading pirated software and playing games. This observation was made during multiple investigations related to Snowflake.
Customers that hire contractors to help them with Snowflake may use unmonitored laptops or personal computers, which worsen this initial entry vector. These devices pose a serious concern because they are frequently used to access the systems of several different organizations. A single contractor’s laptop can enable threat actors to access numerous organizations if it is infected with infostealer malware, frequently with administrator- and IT-level access.
Identifying
The native web-based user interface (SnowFlake UI, also known as SnowSight) and/or command-line interface (CLI) tool (SnowSQL) on Windows Server 2022 were frequently used to get initial access to Snowflake customer instances. Using an attacker-named utility called “rapeflake,” which Mandiant records as FROSTBITE, Mandiant discovered more access.
Mandiant believes FROSTBITE is used to conduct reconnaissance against target Snowflake instances, despite the fact that Mandiant has not yet retrieved a complete sample of FROSTBITE. Mandiant saw the use of FROSTBITE in both Java and.NET versions. The Snowflake.NET driver communicates with the.NET version. The Snowflake JDBC driver is interfaced with by the Java version.
SQL recon actions by FROSTBITE have been discovered, including a listing of users, current roles, IP addresses, session IDs, and names of organizations. Mandiant also saw UNC5537 connect to many Snowflake instances and conduct queries using DBeaver Ultimate, a publicly accessible database management tool.
Finish the mission
Mandiant saw UNC5537 staging and exfiltrating data by continuously running identical SQL statements on many client Snowflake systems. The following instructions for data staging and exfiltration were noted.
Generate (TEMP|TEMPORARY) STAGE UNC5537 used the CREATE STAGE command to generate temporary stages for data staging. The data files that are loaded and unloaded into database tables are stored in tables called stages. When a stage is created and designated as temporary, it is removed after the conclusion of the creator’s active Snowflake session.
UNC5537 Credit
Since May 2024, Mandiant has been monitoring UNC5537, a threat actor with financial motivations, as a separate cluster. UNC5537 often extorts people for financial benefit, having targeted hundreds of organizations globally. Under numerous aliases, UNC5537 participates in cybercrime forums and Telegram channels. Mandiant has recognized individuals who are linked to other monitored groups. Mandiant interacts with one member in Turkey and rates the composition of UNC5537 as having a moderate degree of confidence among its members who are located in North America.
In order to gain access to victim Snowflake instances, Attacker Infrastructure UNC5537 mostly leveraged Mullvad or Private Internet Access (PIA) VPN IP addresses. Mandiant saw that VPS servers from Moldovan supplier ALEXHOST SRL (AS200019) were used for data exfiltration. It was discovered that UNC5537 was storing stolen victim data on other foreign VPS providers in addition to the cloud storage provider MEGA.
Prospects and Significance
The campaign launched by UNC5537 against Snowflake client instances is not the product of a highly advanced or unique method, instrument, or process. The extensive reach of this campaign is a result of both the expanding infostealer market and the passing up of chances to further secure credentials:
UNC5537 most likely obtained credentials for Snowflake victim instances by gaining access to several infostealer log sources. There’s also a thriving black market for infostealerry, with huge lists of credentials that have been stolen available for purchase and distribution both inside and outside the dark web.
Infostealers
Multi-factor authentication was not necessary for the impacted customer instances, and in many cases, the credentials had not been changed in up to four years. Additionally, access to trusted locations was not restricted using network allow lists.
This ad draws attention to the ramifications of a large number of credentials floating throughout the infostealer market and can be a sign of a targeted attack by threat actors on related SaaS services. Mandiant predicts that UNC5337 will carry on with similar intrusion pattern, soon focusing on more SaaS systems.
This campaign’s wide-ranging effects highlight the pressing necessity for credential monitoring, the ubiquitous application of MFA and secure authentication, traffic restriction to approved sites for royal jewels, and alerts regarding unusual access attempts. See Snowflake’s Hardening Guide for additional suggestions on how to fortify Snowflake environments.
