Implementing a multi-layered approach to cybersecurity is crucial to defend against such attacks.
Cyber-attacks have been evolving over the past few years. They constantly seek new ways to access private information or demand money from their victims.
Stealer-as-a-Ransomware (StaR), a ransomware that encrypts files and steals sensitive information from systems, is one of the most recent trends in cybercrime.
Stealer-as-a-Ransomware (StaR) is a new threat in the constantly changing cyber-threat landscape.
This hybrid malware poses a formidable threat to digital security. It combines a stealer’s data-exfiltration abilities with ransomware’s destructive potential.
There is a specific category of malware made specifically for credential theft. These info stealers have also become one of the most common and harmful tools used by cybercriminals over the past year.
What is InfoStealer Malware
According to Trend Micro, stealer malware is defined as:
“An information stealer (or info stealer) is a Trojan designed to gather information from a system. The most common form of info stealer gathers login information, like usernames and passwords, which it sends to another system via email or over a network.
Other common information stealers, such as keyloggers, are designed to log user keystrokes which may reveal sensitive information.”
It carries out this communication covertly with a cybercriminal control center. Once inside, the malware gathers private information like browser data, saved passwords, cryptocurrency information, and more.
On specialized websites and in private chat groups, the cybercriminals then resell the stolen data to other criminals.
Buyers can use this information to launch ransomware attacks and commit financial fraud. They can also pose as victims to access the victims’ accounts and more.
How Stealer Malware Works
Stealer malware functions in two phases. It begins by infiltrating systems as a stealer to steal valuable data. It focuses on sensitive data like login credentials, financial information, and personal identification details.
The attacker’s server receives this data containing a wealth of exploitable information. It switches to ransomware mode after the data exfiltration stage. The files of the victim are encrypted and become inaccessible.
The victim then gets a ransom note demanding payment for the decryption key. They also guarantee that the files will be deleted.
Stealer-as-a-Drop is a ransomware variant. In addition to blocking access to the files, ransomware steals sensitive information from computers. This includes credit card numbers, social security numbers, and login information.
If the victim refuses to pay the ransom, the attackers threaten to publicly release or sell this data. Stealer malware attacks typically start with a malicious download or phishing email that infects the victim’s device.
The ransomware installs a keylogger or other data exfiltration tool and encrypts files once it has accessed the computer system. It is especially dangerous because it has a dual threat.
Even if victims pay the ransom and regain access to their files, the stolen data might still be used in subsequent attacks. These could be targeted phishing or identity theft.
Common variants include:
Dark web marketplaces and forums frequently offer malware as a service. Cybercriminals purchase it and use it to steal data from the targeted computers.
They later resell the data, logs, and other sensitive information to other cybercriminals who use it for their illegal activities on the Dark Web or other encrypted social media channels.
Stealer Malware Detection
While stealer malware operates covertly, some signs may cause concern. Recognize behavioral alterations that might point to the presence of stealth malware.
- Unusual System Slowdown: Stealer malware may be to blame if you notice a significant and unexplained decline in your system’s performance. This could be a sluggish startup, frequent crashes, or slow response times. These malware strains frequently operate in the background, using up system resources and reducing responsiveness.
- Suspicious Network Activity: Observe unusual network activity, such as increased data usage, unknown connections, and unexplained network traffic. To exfiltrate stolen data, stealth malware must communicate with its command and control infrastructure. This can lead to strange, suspicious network patterns.
- Modified Browser Settings: Stealer malware frequently targets web browsers to steal sensitive data, including cookies and passwords. Sudden changes to browser settings may indicate that your browser has been compromised by stealer malware. It includes the default homepage, search engine, or new browser extensions you didn’t install.
- Unauthorized Account Activities: Watch for any unauthorized activity on your online accounts. Your credentials may have been stolen by malware if you notice:
- Unusual login attempts
- Unauthorized transactions
- Changes to your account information without your knowledge.
Review your account activity frequently, and enable notifications for any suspicious activity.
How to Prevent Stealer Malware
Implementing a multi-layered approach to cybersecurity is crucial to defend against such attacks. Here are some best practices to take into account:
- Multi-Factor Authentication (MFA): MFA could help make a first layer of security. It will ensure that users must provide more than just a password when logging in.
- Access Control: Install reliable access control systems to guarantee that only genuine users can access sensitive systems and data. Examples of higher security:
- Using strong passwords,
- implementing role-based access controls,
- routinely reviewing and updating access privileges.
- Protect Your Mobile Devices: Put effective device-level security measures in place. This entails using biometric authentication or creating strong passwords. Firms can encrypt data stored on the device and maintain operating systems. Maintain application updates with the most recent security patches. Inform staff members regularly about secure mobile device usage.
- Download Applications with Caution: Exercise caution when downloading applications, especially from unreliable app stores or unofficial sources. To reduce the risk of downloading malware-infected apps:
- Stick to trusted app stores
- Confirm the app’s legitimacy
- Developer’s legitimacy
- Read reviews and user ratings before installing any app.
- Avoid Phone-to-PC Connections: Be cautious when using a potentially compromised phone to connect to a PC, especially in a business setting. A backdoor that gives attackers access to the corporate network could be created by malware on the phone that spreads to the PC.
- Employee Training: Teach employees to recognize phishing emails and avoid downloading malicious files.
- Utilizing AV and/or XDR/EDR: Install a reputable AV and/or that is capable of detecting and removing ransomware.
- Utilizing CTI: Predictive intelligence always changes the game.
- Backups: Regularly copy all important files to a cloud-based storage service or an external drive.
- Security Patches: Ensure all software and systems are updated with the most recent security patches.
- Multi-factor authentication: To prevent unauthorized access, use multi-factor authentication for critical applications and services.
People and organizations must be vigilant against new and evolving cyber-threats as cybercriminals continue to innovate. Attacks using thieves as ransomware are rising and can seriously harm a company’s finances and reputation.
Firms can better protect themselves and their data against these malicious attacks by implementing the most recent cybersecurity best practices and staying current on the most recent threats.