The threat actors behind a recently observed Qilin ransomware attack have stolen credentials stored in Google Chrome browsers on a small set of compromised endpoints.
The use of credential harvesting in connection with a ransomware infection marks an unusual twist, and one that could have cascading consequences, cybersecurity firm Sophos said in a Thursday report.
The attack, detected in July 2024, involved infiltrating the target network via compromised credentials for a VPN portal that lacked multi-factor authentication (MFA), with the threat actors conducting post-exploitation actions 18 days after initial access took place.
"Once the attacker reached the domain controller in question, they edited the default domain policy to introduce a logon-based Group Policy Object (GPO) containing two items," researchers Lee Kirkpatrick, Paul Jacobs, Harshal Gosalia, and Robert Weiland said.
The first of them is a PowerShell script named "IPScanner.ps1" that's designed to harvest credential data stored within the Chrome browser. The second item is a batch script ("logon.bat") contacting commands to execute the first script.
"The attacker left this GPO active on the network for over three days," the researchers added.
"This provided ample opportunity for users to log on to their devices and, unbeknownst to them, trigger the credential-harvesting script on their systems. Again, since this was all done using a logon GPO, each user would experience this credential-scarfing each time they logged in."
The attackers then exfiltrated the stolen credentials and took steps to erase evidence of the activity before encrypting the files and dropping the ransom note in every directory on the system.
The theft of credentials stored in the Chrome browser means that affected users are now required to change their username-password combinations for every third-party site.
"Predictably, ransomware groups continue to change tactics and expand their repertoire of techniques," the researchers said.
"If they, or other attackers, have decided to also mine for endpoint-stored credentials – which could provide a foot in the door at a subsequent target, or troves of information about high-value targets to be exploited by other means – a dark new chapter may have opened in the ongoing story of cybercrime."
Ever-evolving Trends in Ransomware
The development comes as ransomware groups like Mad Liberator and Mimic have been observed using unsolicited AnyDesk requests for data exfiltration and leveraging internet-exposed Microsoft SQL servers for initial access, respectively.
The Mad Liberator attacks are further characterized by the threat actors abusing the access to transfer and launch a binary called "Microsoft Windows Update" that displays a bogus Windows Update splash screen to the victim to give the impression that software updates are being installed on the machine while the data is being plundered.
The abuse of legitimate remote desktop tools, as opposed to custom-made malware, offers attackers the perfect disguise to camouflage their malicious activities in plain sight, allowing them to blend in with normal network traffic and evade detection.
Ransomware continues to be a profitable venture for cybercriminals despite a series of law enforcement actions, with 2024 set to be the highest-grossing year yet. The year also saw the largest ransomware payment ever recorded at approximately $75 million to the Dark Angels ransomware group.
"The median ransom payment to the most severe ransomware strains has spiked from just under $200,000 in early 2023 to $1.5 million in mid-June 2024, suggesting that these strains are prioritizing targeting larger businesses and critical infrastructure providers that may be more likely to pay high ransoms due to their deep pockets and systemic importance," blockchain analytics firm Chainalysis said.
Ransomware victims are estimated to have paid $459.8 million to cybercriminals in the first half of the year, up from $449.1 million year-over-year. However, total ransomware payment events as measured on-chain have declined YoY by 27.29%, indicating a drop in payment rates.
What's more, Russian-speaking threat groups accounted for at least 69% of all cryptocurrency proceeds linked to ransomware throughout the previous year, exceeding $500 million.
According to data shared by NCC Group, the number of ransomware attacks observed in July 2024 jumped month-on-month from 331 to 395, but down from 502 registered last year. The most active ransomware families were RansomHub, LockBit, and Akira. The sectors that were most frequently targeted include industrials, consumer cyclicals, and hotels and entertainment.
Industrial organizations are a lucrative target for ransomware groups due to the mission-critical nature of their operations and the high impact of disruptions, thus increasing the likelihood that victims could pay the ransom amount demanded by attackers.
"Criminals focus where they can cause the most pain and disruption so the public will demand quick resolutions, and they hope, ransom payments to restore services more quickly," said Chester Wisniewski, global field chief technology officer at Sophos.
"This makes utilities prime targets for ransomware attacks. Because of the essential functions they provide, modern society demands they recover quickly and with minimal disruption."
Ransomware attacks targeting the sector have nearly doubled in Q2 2024 compared to Q1, from 169 to 312 incidents, per Dragos. A majority of the attacks singled out North America (187), followed by Europe (82), Asia (29), and South America (6).
"Ransomware actors are strategically timing their attacks to coincide with peak holiday periods in some regions to maximize disruption and pressure organizations into payment," NCC Group said.
Malwarebytes, in its own 2024 State of Ransomware report, highlighted three trends in ransomware tactics over the past year, including a spike in attacks during weekends and early morning hours between 1 a.m. and 5 a.m., and a reduction in the time from initial access to encryption.
Another noticeable shift is the increased edge service exploitation and targeting of small and medium-sized businesses, WithSecure said, adding the dismantling of LockBit and ALPHV (aka BlackCat) has led to an erosion of trust within the cybercriminal community, causing affiliates to move away from major brands.
Indeed, Coveware said over 10% of the incidents handled by the company in Q2 2024 were unaffiliated, meaning they were "attributed to attackers that were deliberately operating independently of a specific brand and what we typically term 'lone wolves.'"
"Continued takedowns of cybercriminal forums and marketplaces shortened the lifecycle of criminal sites, as the site administrators try to avoid drawing law enforcement (LE) attention," Europol said in an assessment released last month.
"This uncertainty, combined with a surge in exit scams, have contributed to the continued fragmentation of criminal marketplaces. Recent LE operations and the leak of ransomware source codes (e.g., Conti, LockBit, and HelloKitty) have led to a fragmentation of active ransomware groups and available variants."
