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Cybersecurity Best Practices Against DarkSide Ransomware
The ransomware called “Darkside” wreaked havoc lately, with Colonial Pipeline, which operates the largest fuel pipeline in the U.S., as its latest high-profile victim.
Colonial Pipeline became aware of the ransomware attack last May 7, forcing the company to shut down its operations. The company was able to restart its operations last May 12.
A report from Bloomberg showed that Colonial Pipeline paid within hours after the attack the group behind Darkside ransomware nearly $5 million. According to the Bloomberg report, once nearly $5 million was paid, the group behind Darkside ransomware gave the decryption tool for Colonial Pipeline to restore its disabled computer network.
The decryption tool, however, was so slow that the Colonial Pipeline continued using its own backups to help restore the system, the report said.
What Is DarkSide Ransomware?
DarkSide ransomware is a ransomware-as-a-service (RaaS) in which the ransomware developers receive a share of the proceeds from the cybercriminal actors who deploy the ransomware, known as “affiliates.”
This ransomware was first observed in the wild in August 2020 and has been known to target high-revenue organizations. Similar to modern ransomware, DarkSide ransomware encrypts victims’ files and demands from victims ransom payment in exchange for the decryption tool that would unlock the encrypted files.
Aside from data encryption and decryption, DarkSide ransomware also carries out data exfiltration and threatening victims that non-payment of ransom could lead to the public exposure of stolen data. In addition, the group behind DarkSide ransomware is also willing to carry out a Distributed Denial of Service (DDoS) attack against victims.
Tactics Used by DarkSide Ransomware Attackers
Researchers at FireEye in the blog post “Shining a Light on DARKSIDE Ransomware Operations” and researchers at McAfee in the blog post “DarkSide Ransomware Victims Sold Short” found that the group behind the DarkSide ransomware employed the following tactics:
. Password Spraying Attack Against Corporate VPN
To gain initial access to their victim’s network, the group behind DarkSide ransomware used password spraying against corporate VPN. In password spraying, an attacker circumvents the account lock-out countermeasures by trying the same password across many accounts before trying another password.
. Exploitation of CVE-2021-20016
To gain initial access to their victim’s network, the attackers exploited CVE-2021-20016, a SQL-Injection vulnerability in the SonicWall product that allows a remote unauthenticated attacker to perform SQL query to access username password and other session-related information.
. Phishing Emails
To gain initial access to their victim’s network, the attackers also used phishing emails to deliver the SMOKEDHAM – a malicious software (malware) that supports keylogging, taking screenshots and executing arbitrary .NET commands.
. Exploitation of Remote Desktop Protocol (RDP) Vulnerabilities
To gain initial access to their victim’s network, the attackers also exploited RDP, a proprietary protocol developed by Microsoft that allows users the ability to connect to another computer over the internet. In the past few years, a handful of security vulnerabilities on RDP had been identified and patched. Many, however, fail to apply the latest RDP patch.
. Leveraging TeamViewer
To establish persistence within the victim environment, the attackers also leveraged TeamViewer – a legitimate software that allows access to computers and networks remotely.
. Leveraging Mimikatz
To gain more privileges on the victim’s network, the attackers also used Mimikatz for credential harvesting.
. Leveraging NGROK
To bypass firewalls and expose remote desktop service ports, like RDP and WinRM, to the open internet, the attackers used the publicly available NGROK.
. Leveraging Cobalt Strike BEACON
To maintain a foothold on the victim’s network, the attackers used Cobalt Strike BEACON. Cobalt Strike is a commercially available penetration testing tool. The group behind Cobalt Strike describes BEACON as a tool to “egress a network over HTTP, HTTPS, or DNS.”
Cybersecurity Best Practices
Below are some of the cybersecurity best practices in order to reduce your organization’s vulnerability to ransomware such as DarkSide and reduce the risk of severe business degradation once impacted by ransomware:
Use multi-factor authentication as an added protection to the single-factor authentication: the traditional username and password combination.
Filter emails to prevent malicious executable files from reaching end users.
Filter network traffic to prevent inbound and outbound communications with known malicious IP addresses.
Keep all software up to date by applying the latest patches in a timely manner.
Protect RDP with strong passwords, multi-factor authentication, VPN other security protections.
Implement application allow listing, allowing the systems to execute only software programs that are known and permitted by the security policy.
It’s important to note that the tactics above-mentioned aren’t just used by the group behind DarkSide ransomware. The said tactics are widely used as well by ransomware groups and other malware operators. As such, the cybersecurity best practices above-mentioned also apply to other forms of attacks.
To date, the group behind the Darkside ransomware has gone dark, making it unclear whether the group has ceased, suspended operation, or has changed its operations or maneuvering an exit. Since March 13, all the dark websites used by the group behind Darkside are down. These sites were used by the group to communicate with the public.
Steve E. Driz, I.S.P., ITCP