1 min read

New Qakbot Malware Strain Replaces Windows Calculator DLL to Infected PCs

Silviu STAHIE

July 26, 2022

Ad One product to protect all your devices, without slowing them down.
Free 90-day trial
New Qakbot Malware Strain Replaces Windows Calculator DLL to Infected PCs

Security researchers have identified new indicators of compromise for Qakbot malware, which now uses a new DLL sideloading infection technique that seeks to trick an official app into using a malicious DLL file.

Threats never stay the same, and hackers always look to improve their malware to stay ahead of security solutions. Evolving malware might change attack vectors or improve existing ones. In any case, it’s the main reason malware families endure.

The same goes for Qakbot, a malware strain known for of its role in large email spam campaigns. Its inner workings have been well documented, but it looks like its developers have made some changes. When security researcher proxylife and Cyble took a closer look at one of the latest spam email campaigns carrying this malware strain, they noticed something new.

“In this campaign, the spam email contains a password-protected zip file which contains an ISO file,” explainedthe researchers. “When mounted, this ISO file shows a .lnk file masquerading as a PDF file. If the victim opens the .lnk file, the system is infected with Qakbot malware.”

The malware uses DLL sideloading, a technique that lets attackers trick apps into loading malicious .dll files with the same name as the legitimate one.

“In this case, the application is calc.exe, and the malicious file named WindowsCodecs.dll masquerades as a support file for calc.exe,” the researchers explained.

“Upon executing the calc.exe, it further loads WindowsCodec.dll and executes the final Qakbot payload using regsvr32.exe. The final payload injects its malicious code into explorer.exe and performs all the malicious activities.”

The primary purpose of the Qakbot is to steal credentials from infected systems, so the damage such malware can inflict is substantial.

Of course, as usual, we recommend not opening emails or attachments from unknown sources. Always have a security solution installed, such as Bitdefender Ultimate Security, that can prevent infections and other types of attacks.

tags


Author



Right now

Top posts

Threat actors impersonate Canadian gas retailer to deliver malicious OneNote phishing campaign, Bitdefender Labs warns

Threat actors impersonate Canadian gas retailer to deliver malicious OneNote phishing campaign, Bitdefender Labs warns

January 26, 2023

2 min read
Spammers phish eager vacationers with travel-themed lures, Bitdefender Antispam Lab warns

Spammers phish eager vacationers with travel-themed lures, Bitdefender Antispam Lab warns

January 19, 2023

4 min read
Enhance your cyber resilience and privacy on Computer Security Day in four easy steps

Enhance your cyber resilience and privacy on Computer Security Day in four easy steps

November 29, 2022

2 min read
How to monitor your online privacy during your Thanksgiving trip

How to monitor your online privacy during your Thanksgiving trip

November 22, 2022

3 min read
Just your yearly dose of Black Friday spam: Cybercrooks get ahead of the game to steal shoppers’ info

Just your yearly dose of Black Friday spam: Cybercrooks get ahead of the game to steal shoppers’ info

November 16, 2022

6 min read
Bitdefender VPN in 2022: the new, the improved, and the soon-to-be

Bitdefender VPN in 2022: the new, the improved, and the soon-to-be

November 14, 2022

5 min read

FOLLOW US ON

SOCIAL MEDIA


You might also like

More than 50,000 People Affected by US Cellular Data Breach; Leaked Info Hits the Internet More than 50,000 People Affected by US Cellular Data Breach; Leaked Info Hits the Internet
Silviu STAHIE

February 08, 2023

1 min read
Russian Threat Actor Targets Ukraine Ministry and Polish Police in Similar Campaigns Russian Threat Actor Targets Ukraine Ministry and Polish Police in Similar Campaigns
Silviu STAHIE

February 06, 2023

1 min read
U.S. Department of Health and Human Services Hits ‘Banner Health’ with $1.25 Million Fine U.S. Department of Health and Human Services Hits ‘Banner Health’ with $1.25 Million Fine
Silviu STAHIE

February 03, 2023

1 min read