If a suspicious file is found in the system, it is recommended to perform a SHA1 comparison to confirm if it is malware.
Check the logs of the system, the scheduling and delivery mechanism of the system regularly. If abnormal connection or new scheduling is detected, the cause should be clarified in depth immediately.
Check the account usage of the system from time to time and change the account password periodically. Ensure the password is accordance with the principle of complexity.
Identify important data, conduct regular backup operations with the following reference:
Perform important data backups regularly.
The backup data should have appropriate physical and environmental protection.
To ensure the availability of backup data, it should be tested periodically.
The duration of backup data and the requirement of permanent archival preservation should be considered by the data owner.
Confidential data backups should be protected by encryption.
Check the user access permissions for network drives and shared folder to avoid unnecessary access.
Check the update status of the operating system, antivirus software, and applications (e.g. Adobe Flash Player, Java), and regularly review system/application update records to prevent hackers from exploiting system/application security vulnerabilities.
If you are using a USB flash drive to transfer data, it should be checked to verify if it infected by viruses or malware.
If suspected infection is found, the following practices can be considered:
To prevent the spreading, shut down the computer and disconnect the network immediately.
Inform the IT staff or vendor to help salvage files that have not been encrypted.
It is recommended to reinstall the operating system and application, confirm the latest patch is installed before restore the backup data.
Backup data should be checked with anti-virus software to ensure there is no residual malware before it is restored to the computer.
Enhance user education and training to pay attention to the relevant emails and the source of the emails, do not open the attached links or files from unknown sources, in case there are implanted in backdoor programs.