skip-2.0 Backdoor

skip-2.0 is a newly observed backdoor created by the Winnti advanced persistent threat group.

Threat ID:: CC-3271
Category:
Threat Severity:: Low
Threat Vector:
Published:: 24 October 2019 12:00 AM

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

Summary

skip-2.0 is a newly observed backdoor created by the Winnti advanced persistent threat group.

Affected platforms

The following platforms are known to be affected:

Microsoft SQL Server

Microsoft SQL Server - Versions 11 (Server 2012) and 12 (Server 2014)

Threat details

Based on earlier versions of their PortReuse and ShadowPad tools, it is believed to be the first publicly known backdoor to target Microsoft SQL (MSSQL) servers. As with PortReuse, skip-2.0 is delivered embedded within a custom VMProtected launcher, which itself appears to be distributed via compromised hosting servers, supply-chain attacks, or spear-phishing campaigns. When executed, this launcher will attempt to hijack the search order for the TSVIPSrv.dll file to maintain persistence before unpacking and launching a secondary loader, which will then decrypt and execute skip-2.0.

Once installed, skip-2.0 will attempt to inject itself into the sqlserv.exe process so that it may retrieve sqllang.dll. It will then locate and hook several functions related to authentication and event logging within this DLL. If successful, skip-2.0 will begin listening for login requests to the affected system, bypassing authentication measures for any request using a hard-coded 'magic' password.

Remediation steps

Type	Step
	To prevent and detect an infection, ensure that: 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, anti-virus and other security products are kept up-to-date. Regular anti-virus and security scans are performed on your organisation’s estate. All day-to-day computer activities such as email and internet are performed using non-administrative accounts. Strong password policies are in place. Network, proxy and firewall logs should be monitored for suspicious activity. User accounts accessed from affected devices should be reset on a clean computer. Your organisation adopts a holistic all-round approach to Cyber Security as advocated by the 10 Steps to Cyber Security.

Type

Step

To prevent and detect an infection, ensure that:

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, anti-virus and other security products are kept up-to-date.
Regular anti-virus and security scans are performed on your organisation’s estate.
All day-to-day computer activities such as email and internet are performed using non-administrative accounts.
Strong password policies are in place.
Network, proxy and firewall logs should be monitored for suspicious activity.
User accounts accessed from affected devices should be reset on a clean computer.
Your organisation adopts a holistic all-round approach to Cyber Security as advocated by the 10 Steps to Cyber Security.

Last edited: 14 February 2020 2:54 pm