• 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

U.S. CISA adds CrushFTP, Google Chromium, and SysAid flaws to its Known Exploited Vulnerabilities catalog

 | 

U.S. CISA urges FCEB agencies to fix two Microsoft SharePoint flaws immediately and added them to its Known Exploited Vulnerabilities catalog

 | 

Sophos fixed two critical Sophos Firewall vulnerabilities

 | 

French Authorities confirm XSS.is admin arrested in Ukraine

 | 

Microsoft linked attacks on SharePoint flaws to China-nexus actors

 | 

Cisco confirms active exploitation of ISE and ISE-PIC flaws

 | 

SharePoint under fire: new ToolShell attacks target enterprises

 | 

CrushFTP zero-day actively exploited at least since July 18

 | 

Hardcoded credentials found in HPE Aruba Instant On Wi-Fi devices

 | 

MuddyWater deploys new DCHSpy variants amid Iran-Israel conflict

 | 

U.S. CISA urges to immediately patch Microsoft SharePoint flaw adding it to its Known Exploited Vulnerabilities catalog

 | 

Microsoft issues emergency patches for SharePoint zero-days exploited in "ToolShell" attacks

 | 

SharePoint zero-day CVE-2025-53770 actively exploited in the wild

 | 

Singapore warns China-linked group UNC3886 targets its critical infrastructure

 | 

U.S. CISA adds Fortinet FortiWeb flaw to its Known Exploited Vulnerabilities catalog

 | 

SECURITY AFFAIRS MALWARE NEWSLETTER ROUND 54

 | 

Security Affairs newsletter Round 533 by Pierluigi Paganini – INTERNATIONAL EDITION

 | 

Radiology Associates of Richmond data breach impacts 1.4 million people

 | 

Fortinet FortiWeb flaw CVE-2025-25257 exploited hours after PoC release

 | 

Authorities released free decryptor for Phobos and 8base ransomware

 | 
  • 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
  • Breaking News
  • Cyber Crime
  • Malware
  • Wekby APT group leverages DNS requests for C2 communications

Wekby APT group leverages DNS requests for C2 communications

Pierluigi Paganini May 28, 2016

PaloAlto Networks has spotted a new campaign conducted by the Wekby APT that leverages on a malware that uses DNS requests for C2 communications.

Security experts at Palo Alto Networks have spotted a China-linked APT group that has been using a strain of malware that leverages DNS requests for command and control (C&C) communications.

The group is known as Wekby, Dynamite Panda, TG-0416 and APT 18, security experts linked it to the security breach suffered by the Community Health Systems in 2014.

The attackers exploited the Heartbleed vulnerability affecting the OpenSSL to steal 4.5 million patient records.

In July 2015, the Wekby APT group was spotted exploiting the CVE-2015-5119 Flash Player vulnerability in their exploit kits, the exploit code was disclosed as the result of the attack against the Hacking Team.

In the last wave of attacks discovered by the experts at PaloAlto, the Wekby APT group targeted US-based organization using a strain of malware dubbed ‘pisloader.’

The pisloader malware is a variant of the HTTPBrowser RAT that was delivered via HTTP from the following URL:

http://globalprint-us[.]com/proxy_plugin.exe 

The threat actors deliver a malware dropper that adds registry keys for persistence and decrypts and executes the pisloader payload which is obfuscated using a return-oriented programming (ROP) technique.

“This particular command will set the HKCU\Software\Microsoft\Windows\CurrentVersion\Run\lsm registry key with a value of “%appdata%\lsm.exe”. After this key is set, the malware proceeds to decrypt a two blobs of data with a single-byte XOR key of 0x54. The resulting data is written to the %appdata%\lsm.exe file path.

After this file is written, the malware executes the newly written lsm.exe file, which contains the Pisloader payload.”

The novelty discovered by the researchers at PaloAlto Networks is that the Pisloader leveraged DNS requests for C&C communications, in this way the malicious code is able to masquerade its activity.

The abuse of DNS queries was already observed by malware researchers, in March 2016 the experts from FireEye discovered a strain of POS malware dubbed Multigrain that steals card data from point-of-sale systems and exfiltrates it over DNS.

The Pisloade periodically sends a DNS beacon request to the C&C server that is hardcoded into the malware.

“The pisloader sample will send a beacon periodically that is composed of a random 4-byte uppercase string that is used as the payload. An example of this can be found below:

Wekby pisloader beacon

 

Figure 5 pisloader DNS beacon request

“The malicious code expects various aspects of the DNS responses to be set in a specific way, or else pisloader will ignore the DNS reply.”

The C2 server replies with a TXT record that can contain various commands for the malware.

The discovery made by experts at PaloAlto Networks demonstrates that the Wekby group is still active and it is involved in high-profile cyber-espionage campaigns using sophisticated malware.

If you appreciate my effort in spreading cyber security awareness, please vote for Security Affairs as best European Security Blog. Vote SecurityAffairs in every section it is reported. I’m one of the finalists and I want to demonstrate that the Security Affairs community a great reality.

https://www.surveymonkey.com/r/secbloggerwards2016

Thank you

Pierluigi

[adrotate banner=”9″]

Pierluigi Paganini

(Security Affairs – Wekby APT, China)


facebook linkedin twitter

APT China cyber espionage malware Wekby

you might also like

Pierluigi Paganini July 24, 2025
U.S. CISA adds CrushFTP, Google Chromium, and SysAid flaws to its Known Exploited Vulnerabilities catalog
Read more
Pierluigi Paganini July 23, 2025
U.S. CISA urges FCEB agencies to fix two Microsoft SharePoint flaws immediately and added them to its Known Exploited Vulnerabilities catalog
Read more

leave a comment

newsletter

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

    recent articles

    U.S. CISA adds CrushFTP, Google Chromium, and SysAid flaws to its Known Exploited Vulnerabilities catalog

    Hacking / July 24, 2025

    U.S. CISA urges FCEB agencies to fix two Microsoft SharePoint flaws immediately and added them to its Known Exploited Vulnerabilities catalog

    Hacking / July 23, 2025

    Sophos fixed two critical Sophos Firewall vulnerabilities

    Security / July 23, 2025

    French Authorities confirm XSS.is admin arrested in Ukraine

    Cyber Crime / July 23, 2025

    Microsoft linked attacks on SharePoint flaws to China-nexus actors

    APT / July 23, 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