Best practices to prevent ransomware attacks:
- Perform regular backups of all critical information to limit the impact of data or system loss and to help expedite the recovery process. Ideally, this data should be kept on a separate device, and backups should be stored offline.
- Establish a Sender Policy Framework (SPF), Domain Message Authentication Reporting and Conformance (DMARC), and DomainKeys Identified Mail (DKIM) for your domain, which is an email validation system designed to prevent spam by detecting email spoofing by which most of the ransomware samples successfully reaches the corporate email boxes.
- Don’t open attachments in unsolicited e-mails, even if they come from people in your contact list, and never click on a URL contained in an unsolicited e-mail, even if the link seems benign. In cases of genuine URLs close out the e-mail and go to the organisation’s website directly through browser
- Restrict execution of PowerShell /WSCRIPT in enterprise environment Ensure installation and use of the latest version (currently v5.0) of PowerShell, with enhanced logging enabled. script block logging and transcription enabled. Send the associated logs to a centralised log repository for monitoring and analysis.
- Application whitelisting/Strict implementation of Software Restriction Policies (SRP) to block binaries running from %APPDATA%, %PROGRAMDATA% and %TEMP% paths. Ransomware sample drops and executes generally from these locations. Enforce application whitelisting on all endpoint workstations.
- Deploy web and email filters on the network. Configure these devices to scan for known bad domains, sources, and addresses; block these before receiving and downloading messages. Scan all emails, attachments, and downloads both on the host and at the mail gateway with a reputable antivirus solution.
- Disable macros in Microsoft Office products. Some Office products allow for the disabling of macros that originate from outside of an organisation and can provide a hybrid approach when the organisation depends on the legitimate use of macros. For Windows, specific settings can block macros originating from the Internet from running.
- Configure access controls including file, directory, and network share permissions with least privilege in mind. If a user only needs to read specific files, they should not have write access to those files, directories, or shares.
- Maintain updated Antivirus software on all systems
- Consider installing Enhanced Mitigation Experience Toolkit, or similar host-level anti-exploitation tools.
- Block the attachments of file types, exe|pif|tmp|url|vb|vbe|scr|reg|cer|pst|cmd|com|bat|dll|dat|hlp|hta|js|wsf
- Regularly check the contents of backup files of databases for any unauthorized encrypted contents of data records or external elements, (backdoors /malicious scripts.)
- Keep the operating system third party applications (MS office, browsers, browser Plugins) up-to-date with the latest patches.
- Follow safe practices when browsing the web. Ensure the web browsers are secured enough with appropriate content controls.
- Network segmentation and segregation into security zones – help protect sensitive information and critical services. Separate administrative network from business processes with physical controls and Virtual Local Area Networks.
- Disable remote Desktop Connections, employ least-privileged accounts.
- Ensure integrity of the codes /scripts being used in database, authentication and sensitive systems, Check regularly for the integrity of the information stored in the databases.
- Restrict users’ abilities (permissions) to install and run unwanted software applications.
- Enable personal firewalls on workstations.
- Implement strict External Device (USB drive) usage policy.
- Employ data-at-rest and data-in-transit encryption.
- Carry out vulnerability Assessment and Penetration Testing (VAPT) and information security audit of critical networks/systems, especially database servers from CERT-IN empaneled auditors. Repeat audits at regular intervals.
- Individuals or organisations are not encouraged to pay the ransom, as this does not guarantee files will be released. Report such instances of fraud to CERT-In and Law Enforcement agencies
Reference by google.com
Spora is a recent addition to the ransomware family that Quick Heal Lab has come across. It is a file encryptor ransomware that encrypts a user’s files with strong encryption algorithm and demands a ransom. Spora is launched with a good infection routine, the capability to work offline, well-designed and managed payment portal dashboard, decryption key purchase options.
Spora is delivered to the victim via spam emails containing a malicious .ZIP file as an attachment. This .ZIP file contains an HTML Application (‘.HTA’) file that pretends to be an invoice in .PDF or .DOC format, wearing double extensions to those files (e.g. <file_name>.pdf.HTA). As ‘Hide extensions for known file types’ option is marked checked by default in many systems, it increases the chances of getting trapped in opening an .HTA file by mistaking it for harmless file types.
Spora has a multistage infection behavior. When a malicious .HTA file is executed, it drops and executes the below files into the system using VBScript program:
• It is actually a file encryptor component that performs file encryption.
• doc_6d518e.docx is a corrupt file that is intentionally dropped and opened to keep the victim busy in viewing it while files are getting encrypted in the background.
Spora was not found appending any extension to the encrypted files. When encryption is over, a ransom note is displayed (shown below), highlighting the uniquely generated ‘Infection ID’ and basic instructions.
A .KEY file is dropped on the desktop, containing information about ‘encrypted-encryption keys’ used to encrypt files. In order for the victim to get complete access to the payment portal, they need to upload .KEY file to the portal to synchronize the infected computer with the payment portal. To do so, the below panel is provided.
Once synchronized, the victim can choose from a number of purchase options available on a ‘My Purchase’ section of the portal.
FULL RESTORE – With this, the user can have all their encrypted data restored.
IMMUNITY – With this, the user can buy immunity against future Spora attacks.
REMOVAL – With this, the user can have the Spora malware completely removed from their computer.
FILE RESTORE – Offers two options; decrypt two files for free or decrypt a selection of files for $30.
As you can see, Spora offers the victim with a variety of options to take care of the situation. For instance, a victim might be less likely to pay the ransom because they know they have safely backed up their data. However, they would still want to have the malware removed from the system – which gives the ‘Removal’ option.
Quick Heal Detection
Quick Heal antivirus successfully prevents Spora infections at multiple stages.
• Quick Heal Email Protection successfully prevents download of the malicious .ZIP attachment which is the first stage of the infection.
As shown in the image above, the malicious .HTA file has been successfully detected as ‘JS.Nemucod.BJF’ and deleted thereafter.
• Quick Heal Anti-ransomware protection successfully detects potential file encryption activities and alerts the user
• Quick Heal Behavior Detection System successfully detects malicious activities and alerts the user
It is not hard to guess that the creators of Spora have taken their time in developing this ransomware to make it effective, and professional at the same time.
A nicely designed decryptor portal dashboard, synchronization between the portal and infected system using a .KEY file, and multiple purchase option for decryption signify how attackers are using complex tactics in creating ransomware.
How to stay safe against such ransomware attacks
- Never download attachments that arrive in emails from unknown or unexpected sources.
- Take regular backups of your files. Remember to disconnect the Internet when you are backing up on a hard drive. Unplug the drive before you go online again.
- Apply all recommended security updates (patches) to your Operating System, and programs like Adobe, Java, web browsers, etc.
- Install an antivirus software that offers several layers of security. More importantly, keep the software up-to-date.
Reference by Quick Heal