Cyber risk and advisory programs that identify security gaps and build strategies to address them.
MDR that provides improved detection, 24/7 threat hunting, end-to-end coverage and most of all, complete Response.
Our team delivers the fastest response time in the industry. Threat suppression within just 4 hours of being engaged.
Be protected by the best from Day 1.
24/7 Threat Investigation and Response.
Expert hunting, research and content.
Defend brute force attacks, active intrusions and unauthorized scans.
Safeguard endpoints 24/7 by isolating and remediating threats to prevent lateral spread.
Investigation and enhanced threat detection across multi-cloud or hybrid environments.
Configuration escalations, policy and posture management.
Detects malicious insider behavior leveraging Machine Learning models.
Customer testimonials and case studies.
Stories on cyberattacks, customers, employees, and more.
Cyber incident, analyst, and thought leadership reports.
Demonstrations, seminars and presentations on cybersecurity topics.
Information and solution briefs for our services.
MITRE ATT&CK Framework, Cybersecurity Assessment, SOC Calculator & more
In the first week of April 2023, the eSentire Threat Intelligence team observed a significant increase in Qakbot incidents impacting various industries. Qakbot is an information-stealing malware. Qakbot is commonly delivered using phishing methods, including malicious emails from previously unseen email addresses or as replies to existing email conversations.
In these incidents, Qakbot gained initial access through phishing emails containing a Zip archive containing a Windows script file (.wsf), a PDF document, or an HTML file using the HTML smuggling method. The malware can also retrieve CobaltStrike from a command-and-control site, and perform basic reconnaissance. However, observed attacks were isolated and alerted on, and the customers were notified for remediation.
Qakbot is highly concerning as the malware has been observed leading to the delivery of multiple ransomware variants. eSentire is sharing details on these attacks, including indicators of compromise (IOCs), to increase awareness of this threat across our customers.
Qakbot malware has been in active use since at least 2007 [1]. Initially, the malware was used to steal victim data, but in recent years it has functioned primarily for reconnaissance and ransomware delivery.
In recently observed incidents, Qakbot was identified gaining initial access through phishing emails. The users received either a Zip archive containing a Windows Script file (.wsf), a PDF document, or an HTML file where they utilized the HTML smuggling method. This is a notable change from the February Qakbot campaign, where all observed threats were delivered via malicious OneNote attachments. It is likely that threat actors distributing Qakbot are testing alternative delivery mechanisms, as Microsoft announced new security measures that will be applied to Microsoft 365 to combat OneNote abuse starting in April 2023.
In the first pair of incidents, eSentire MDR for Endpoint was able to block the activity from continuing past the initial file execution. eSentire MDR for Endpoint also blocked the activity as it reached the PowerShell scripting stage, which involved a PowerShell script attempting to reach domains associated with a Qakbot infection.
In later observed incidents, eSentire identified a version of Qakbot that retrieved Cobalt Strike immediately. If not identified and remediated immediately, the malware would load Cobalt Strike into the machine's registry and perform basic reconnaissance, though eSentire MDR for Endpoint was able to block any connections attempted. The Cobalt Strike framework is a common ransomware precursor threat.
In all recent incidents, eSentire's proactive threat intelligence feeds and global block lists detected activity on the hosts, which were isolated, alerted, and escalated to the customers for remediation. Due to rapid remediation, secondary payloads and attacker objectives have not been identified.
Indicators of Compromise (IoCs):
Type | IoC | Description |
IP Address | 23[.]81[.]246[.]2 | Cobalt Strike |
IP Address | 94[.]131[.]117[.]111 | Qakbot |
IP Address | 199[.]247[.]30[.]203 | Qakbot |
IP Address | 141[.]94[.]86[.]90 | Qakbot |
IP Address | 104[.]225[.]129[.]114 | Qakbot |
IP Address | 216[.]146[.]25[.]129 | Qakbot |
IP Address | 85[.]239[.]41[.]205 | Qakbot |
File | 6291579CD41491CC045D7E0ED05B9A3A72C5CCA6F74F8BDEBC1C85459C423B60 | Cobalt Strike |
File | 8C8CF24571C836636A25040CE36EEA9036B0CC4F09DA14780ED2618A488FDFE8 | Qakbot |
File | EC3F1349AC0196FF3EBCC30435B16B7E290FA8C2FDC0223F72AD9BC08C7B4486 | Qakbot |
File | 0A354C9637EFA27F5B41A525574CB8FC496677E16CE06832CCF0AF699FCCEECA | Qakbot |
References:
[1] https://attack.mitre.org/software/S0650/
[2] https://www.esentire.com/security-advisories/new-qakbot-campaign-observed
[3] https://www.microsoft.com/en-us/security/blog/2021/11/11/html-smuggling-surges-highly-evasive-loader-technique-increasingly-used-in-banking-malware-targeted-attacks/
[4] https://www.esentire.com/security-advisories/ongoing-qakbot-onenote-campaign
[5] OneNote blocks embedded files that have dangerous extensions - Deploy Office | Microsoft Learn