Cloud Email Ransomware

A new unnamed ransomware has been observed that targets cloud email platforms.

Threat ID:: CC-1941
Category:: Exploit
Threat Severity:: Low
Threat Vector:: Email
Published:: 17 January 2018 12:00 AM

Report a cyber attack: call 0300 303 5222 or email [email protected]

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Summary

A new unnamed ransomware has been observed that targets cloud email platforms.

Threat details

Users receive an email that uses social engineering techniques to encourage them to allow full access to their mailbox for a malicious external application. The user clicks on a link in the email and then approves a prompt from the email platform to grant the requested access.

The malicious application can then encrypt all messages in the user's mailbox. It then displays a message demanding payment for the return of this data.

Remediation advice

To avoid becoming infected with ransomware, ensure that:

Remediation steps

Type	Step
	A robust program of education and awareness training is delivered to users to ensure they don’t open attachments or follow links within unsolicited emails. All operating systems, antivirus and other security products are kept up to date. All day to day computer activities such as email and internet are performed using non-administrative accounts and that permissions are always assigned on the basis of least privilege. Your organisation adopts a holistic all round approach to Cyber Security as advocated by the 10 Steps To Cyber Security. To limit the damage of ransomware and enable recovery: All critical data must be backed up, and these backups must be sufficiently protected/kept out of reach of ransomware. Multiple backups should be created including at least one off-network backup (e.g. to tape). Any access granted to unknown applications must be revoked before backups are restored. The only guaranteed way to recover from a ransomware infection is to restore all affected files from their most recent backup.

Type

Step

A robust program of education and awareness training is delivered to users to ensure they don’t open attachments or follow links within unsolicited emails.
All operating systems, antivirus and other security products are kept up to date.
All day to day computer activities such as email and internet are performed using non-administrative accounts and that permissions are always assigned on the basis of least privilege.
Your organisation adopts a holistic all round approach to Cyber Security as advocated by the 10 Steps To Cyber Security.

To limit the damage of ransomware and enable recovery:

All critical data must be backed up, and these backups must be sufficiently protected/kept out of reach of ransomware.

Multiple backups should be created including at least one off-network backup (e.g. to tape).
Any access granted to unknown applications must be revoked before backups are restored.

The only guaranteed way to recover from a ransomware infection is to restore all affected files from their most recent backup.

Last edited: 11 January 2022 11:58 am