• Home
  • Cyber Crime
  • Cyber warfare
  • APT
  • Data Breach
  • Deep Web
  • Digital ID
  • Hacking
  • Hacktivism
  • Intelligence
  • Internet of Things
  • Laws and regulations
  • Malware
  • Mobile
  • Reports
  • Security
  • Social Networks
  • Terrorism
  • ICS-SCADA
  • POLICIES
  • Contact me
MUST READ

Pro-Ukraine hacktivists claim cyberattack on Russian Airline Aeroflot that caused the cancellation of +100 flights

 | 

Seychelles Commercial Bank Reported Cybersecurity Incident

 | 

Microsoft uncovers macOS flaw allowing bypass TCC protections and exposing sensitive data

 | 

U.S. CISA adds Cisco ISE and PaperCut NG/MF flaws to its Known Exploited Vulnerabilities catalog

 | 

Critical WordPress Post SMTP plugin flaw exposes 200K+ sites to full takeover

 | 

Scattered Spider targets VMware ESXi in using social engineering

 | 

China-linked group Fire Ant exploits VMware and F5 flaws since early 2025

 | 

Allianz Life data breach exposed the data of most of its 1.4M customers

 | 

SECURITY AFFAIRS MALWARE NEWSLETTER ROUND 55

 | 

Security Affairs newsletter Round 534 by Pierluigi Paganini – INTERNATIONAL EDITION

 | 

Law enforcement operations seized BlackSuit ransomware gang’s darknet sites

 | 

Arizona woman sentenced for aiding North Korea in U.S. IT job fraud scheme

 | 

Operation CargoTalon targets Russia’s aerospace with EAGLET malware,

 | 

Unpatched flaw in EoL LG LNV5110R cameras lets hackers gain Admin access

 | 

Koske, a new AI-Generated Linux malware appears in the threat landscape

 | 

Mitel patches critical MiVoice MX-ONE Auth bypass flaw

 | 

Coyote malware is first-ever malware abusing Windows UI Automation

 | 

SonicWall fixed critical flaw in SMA 100 devices exploited in Overstep malware attacks

 | 

DSPM & AI Are Booming: $17.87B and $4.8T Markets by 2033

 | 

Stealth backdoor found in WordPress mu-Plugins folder

 | 
  • Home
  • Cyber Crime
  • Cyber warfare
  • APT
  • Data Breach
  • Deep Web
  • Digital ID
  • Hacking
  • Hacktivism
  • Intelligence
  • Internet of Things
  • Laws and regulations
  • Malware
  • Mobile
  • Reports
  • Security
  • Social Networks
  • Terrorism
  • ICS-SCADA
  • POLICIES
  • Contact me
  • Home
  • APT
  • Breaking News
  • Malware
  • Winnti APT group uses skip-2.0 malware to control Microsoft SQL Servers

Winnti APT group uses skip-2.0 malware to control Microsoft SQL Servers

Pierluigi Paganini October 21, 2019

Security experts have a new malware, dubbed skip-2.0 used by the China-linked APT group to establish a backdoor in Microsoft SQL Server systems.

Security experts at ESET have discovered a new malware, dubbed skip-2.0, used by the Chinese Winnti cyberespionage group to gain persistence on Microsoft SQL Server systems.

The Winnti group was first spotted by Kaspersky in 2013, according to the researchers the gang has been active since 2007.

The experts believe that under the Winnti umbrella there are several APT groups, including  Winnti, Gref, PlayfullDragon, APT17, DeputyDog, Axiom, BARIUM, LEAD, PassCV, Wicked Panda, and ShadowPad.

The skip-2.0 malware was used by threat actors to establish a backdoor in MSSQL Server 11 and 12 servers, allowing them to access to any account on the server using a “magic password.” The malicious code is able to remain under the radar thanks to the ability to interact with logging mechanisms.

“Earlier this year, we received a sample of this new backdoor called skip-2.0 by its authors and part of the Winnti Group’s arsenal.” reads the analysis published by ESET researcher Mathieu Tartare. “This backdoor targets MSSQL Server 11 and 12, allowing the attacker to connect stealthily to any MSSQL account by using a magic password – while automatically hiding these connections from the logs. Such a backdoor could allow an attacker to stealthily copy, modify or delete database content.”

The skip-2.0 backdoor has some similarities with other malware in the Winnti Group’s arsenal, such as the PortReuse and ShadowPad backdoors.

The PortReuse backdoor has a modular architecture, experts discovered that its components are separate processes that communicate through named pipes. Experts detected multiple PortReuse variants with a different NetAgent but using the same SK3. Each variant spotted by the experts was targeting different services and ports, including DNS over TCP (53), HTTP (80), HTTPS (443), Remote Desktop Protocol (3389) and Windows Remote Management (5985).

PortReuse was used by the Winnti cyberespionage group to target a high-profile Asian mobile software and hardware manufacturer.

The ShadowPad backdoor is a modular platform that can be used to download and execute arbitrary code on the infected system, create processes, and maintain a virtual file system in the registry,

The remote access capability implemented for the ShadowPad backdoor includes a domain generation algorithm (DGA) for C&C servers which changes every month.

Experts noticed that the three malware use the same VMProtected launcher, the same packer.

The Inner-Loader observed in recent attacks looks for the sqlserv.exe process associated with Microsoft SQL Server, then it injects a payload into this process via the sqllang.dll, giving the malware the ability to hook multiple logging and authentication functions.

“The functions targeted by skip-2.0 are related to authentication and event logging.” continues the analysis.

“The most interesting function is the first one (CPwdPolicyManager::ValidatePwdForLogin), which is responsible for validating the password provided for a given user. This function’s hook checks whether the password provided by the user matches the magic password, in that case, the original function will not be called and the hook will return 0, allowing the connection even though the correct password was not provided.”

Experts pointed out that administrative privileges are required for installing the hooks, this means that skip-2.0 could be delivered only on already compromised MSSQL Servers to achieve persistence.

[adrotate banner=”9″] [adrotate banner=”12″]

Pierluigi Paganini

(SecurityAffairs – Winnti, skip-2.0)

[adrotate banner=”5″]

[adrotate banner=”13″]


facebook linkedin twitter

backdoor Hacking hacking news information security news malware Microsoft SQL Server Pierluigi Paganini Security News

you might also like

Pierluigi Paganini July 29, 2025
Pro-Ukraine hacktivists claim cyberattack on Russian Airline Aeroflot that caused the cancellation of +100 flights
Read more
Pierluigi Paganini July 29, 2025
Seychelles Commercial Bank Reported Cybersecurity Incident
Read more

leave a comment

newsletter

Subscribe to my email list and stay
up-to-date!

    recent articles

    Pro-Ukraine hacktivists claim cyberattack on Russian Airline Aeroflot that caused the cancellation of +100 flights

    Hacktivism / July 29, 2025

    Seychelles Commercial Bank Reported Cybersecurity Incident

    Data Breach / July 29, 2025

    Microsoft uncovers macOS flaw allowing bypass TCC protections and exposing sensitive data

    Hacking / July 29, 2025

    U.S. CISA adds Cisco ISE and PaperCut NG/MF flaws to its Known Exploited Vulnerabilities catalog

    Security / July 28, 2025

    Critical WordPress Post SMTP plugin flaw exposes 200K+ sites to full takeover

    Security / July 28, 2025

    To contact me write an email to:

    Pierluigi Paganini :
    pierluigi.paganini@securityaffairs.co

    LEARN MORE

    QUICK LINKS

    • Home
    • Cyber Crime
    • Cyber warfare
    • APT
    • Data Breach
    • Deep Web
    • Digital ID
    • Hacking
    • Hacktivism
    • Intelligence
    • Internet of Things
    • Laws and regulations
    • Malware
    • Mobile
    • Reports
    • Security
    • Social Networks
    • Terrorism
    • ICS-SCADA
    • POLICIES
    • Contact me

    Copyright@securityaffairs 2024

    We use cookies on our website to give you the most relevant experience by remembering your preferences and repeat visits. By clicking “Accept All”, you consent to the use of ALL the cookies. However, you may visit "Cookie Settings" to provide a controlled consent.
    Cookie SettingsAccept All
    Manage consent

    Privacy Overview

    This website uses cookies to improve your experience while you navigate through the website. Out of these cookies, the cookies that are categorized as necessary are stored on your browser as they are essential for the working of basic functionalities...
    Necessary
    Always Enabled
    Necessary cookies are absolutely essential for the website to function properly. This category only includes cookies that ensures basic functionalities and security features of the website. These cookies do not store any personal information.
    Non-necessary
    Any cookies that may not be particularly necessary for the website to function and is used specifically to collect user personal data via analytics, ads, other embedded contents are termed as non-necessary cookies. It is mandatory to procure user consent prior to running these cookies on your website.
    SAVE & ACCEPT