Avoid installation of malware via Institut za zdravstvo Srbije email

Also Known As: GuLoader malware
Type: Trojan
Distribution: Low
Damage level: Medium

"Institut za zdravstvo Srbije" removal guide

What is "Institut za zdravstvo Srbije"?

It is not uncommon that cyber criminals attempt to exploit the coronavirus crisis in various ways. This malspam campaign is disguised as a COVID-19 themed letter from Institute of Health of Serbia regarding distribution of protective equipment, cyber criminals behind it attempt to trick recipients into infecting their computers with GuLoader through the malicious executable in the attached archive file. Therefore, it is strongly recommend not to trust this email and leave its attachment unopened.

Institut za zdravstvo Srbije malware-spreading email spam campaign

As stated in this email, companies registered in Serbia can receive free protective equipment that supposed to help with the COVID-19 infection prevention. It can be done by filling out the form and sending it to the provided email address. Recipients supposed to find that form in the attached archive file ("obrazac zahtjeva za preventivnu opreme.pdf.zip"). Although, this file contains a malicious executable ("obrazac zahtjeva za preventivnu opreme.pdf.exe") which, if executed, installs GuLoader. GuLoader is a malicious program which is used by cyber criminals to distribute other malware. Simply said, if a computer is infected with GuLoader, then it is very likely that it will get infected with some Remote Access Trojan (RAT), ransomware, cryptocurrency miner, or other high-risk malware. Having a computer infected with such malware be the reason behind problems like identity theft, monetary, data loss, issues related to online privacy, browsing safety, etc. Therefore, it is strongly recommended to ignore email like this one and not to open files (or website links) that are attached to/included in them.

Threat Summary:
Name GuLoader malware
Threat Type Trojan, password-stealing virus, banking malware, spyware.
Hoax Recipients are offered to apply for a free protection equipment
Attachment(s) obrazac zahtjeva za preventivnu opreme.pdf.zip (its name may vary)
Detection Names Avast (FileRepMalware), BitDefender (Gen:Variant.Razy.677016), ESET-NOD32 (Win32/TrojanDownloader.Agent.FCI), Kaspersky (UDS:DangerousObject.Multi.Generic), Full List Of Detections (VirusTotal)
Rogue Process Name obrazac zahtjeva za preventivnu opreme.pdf.exe (its name may vary)
Symptoms Trojans are designed to stealthily infiltrate the victim's computer and remain silent, and thus no particular symptoms are clearly visible on an infected machine.
Payload GuLoader
Distribution methods Infected email attachments, malicious online advertisements, social engineering, software 'cracks'.
Damage Stolen passwords and banking information, identity theft, the victim's computer added to a botnet.
Malware Removal (Windows)

To eliminate possible malware infections, scan your computer with legitimate antivirus software. Our security researchers recommend using Malwarebytes.
▼ Download Malwarebytes
To use full-featured product, you have to purchase a license for Malwarebytes. 14 days free trial available.

Some more examples of malspam are "Spring Company Invoice Email Virus", "Supreme Court Email Virus", "Office Depot Email Virus". Typically, such emails are disguised as important, official and sent with a purpose to deceive users into opening some malicious attachment or of file downloaded through included website link that would infect a computer with some malware. In this particular case by executing a malicious file in the attached ZIP file recipients would install GuLoader. Some examples of malicious programs that could be installed through GuLoader are Agent Tesla, FormBook, LokiBot, NetWire, Remcos and Vidar.

How did "Institut za zdravstvo Srbije" infect my computer?

The operating system could be infected through this email only if users would extract the attached "obrazac zahtjeva za preventivnu opreme.pdf.zip" file and execute the "obrazac zahtjeva za preventivnu opreme.pdf.exe" file (their names may vary). Then installed GuLoader could be used to infect a system with even more malware. More examples of files that cyber criminals attach to their emails are PDF, Microsoft Office documents, other archive files (like RAR), executable files (like .exe), JavaScript files. It is worthwhile to mention that malicious documents that are opened with Microsoft Office 2010 or newer infect computers only when users allow those documents to enable macros commands (editing/content). Although, when such documents are opened with older versions, then they install malware automatically. It is because the aforementioned versions do not include the "Protected View" mode.

How to avoid installation of malware?

Attachments and website links in irrelevant emails that are received from unknown, suspicious addresses should not be opened. It is important to analyze such emails and open their contents only when there is no reason to believe that it may be not safe. Files and programs should be downloaded via direct links and trustworthy, official websites. Other download channels tools should not be trusted. Some examples of unreliable download (and installation) channels are third party downloaders, installers, Peer-to-Peer networks (e.g., eMule, torrent clients), free file hosting pages. Installed software (or operating system) must be updated or activated with tools and/or implemented functions that are provided by software developers. Various 'cracking' (unofficial activation) and third party updaters should not be used. Also, it is not legal to activate software with third party, unofficial tools. Operating system should be regularly scanned for threats with a reputable antivirus or anti-spyware suite, it is important to always keep such software up to date. If you've already opened "Institut za zdravstvo Srbije" attachment, we recommend running a scan with Malwarebytes for Windows to automatically eliminate infiltrated malware.

Text presented in the "Institut za zdravstvo Srbije" email letter:

Subject: Distribucija zaštitne opreme Covid-19 (Ministarstvo zdravlja Srbije) Juna 2020


Mi Institut za zdravstvo Srbije u saradnji sa Ministarstvom zdravlja Srbije i prema direktivi naše Vlade Srbije o odgovoru na covid-19, vršiće se besplatna distribucija zaštitne opreme covid-19 svim registrovanim kompanijama i preduzećima u Srbiji. Jasno ispunite prižoleni obrazac, budite sigurni da su u ovom obrascu dobro napisani tačan broj zaposlenih i adresa kompanije.


Ispunite prižoleni obrazac i vratite nam kopiju prije zatvaranja rada danas, čekajući vaš brzi odgovor.


Svi popunjeni obrazac treba poslati na ovaj e-mail: -



Head of Healthcare Quality Improvement Unit
Institut za javno zdravlje Srbije
"Dr Milan Jovanović Batut"
Dr Subotića 5,  11000 Beograd

Malicious executable detected as a threat by multiple detection engines in virustotal

malicious executable detected as a threat by multiple detection engines in virustotal

Malicious exexutable running in Task Manager as "obrazac zahtjeva za preventivnu opreme.pdf.exe":

obrazac zahtjeva za preventivnu opreme.pdf.exe running in task manager

Instant automatic malware removal: Manual threat removal might be a lengthy and complicated process that requires advanced computer skills. Malwarebytes is a professional automatic malware removal tool that is recommended to get rid of malware. Download it by clicking the button below:
▼ DOWNLOAD Malwarebytes By downloading any software listed on this website you agree to our Privacy Policy and Terms of Use. To use full-featured product, you have to purchase a license for Malwarebytes. 14 days free trial available.

Quick menu:

How to remove malware manually?

Manual malware removal is a complicated task - usually it is best to allow antivirus or anti-malware programs to do this automatically. To remove this malware we recommend using Malwarebytes for Windows. If you wish to remove malware manually, the first step is to identify the name of the malware that you are trying to remove. Here is an example of a suspicious program running on a user's computer:

malicious process running on user's computer sample

If you checked the list of programs running on your computer, for example, using task manager, and identified a program that looks suspicious, you should continue with these steps:

manual malware removal step 1Download a program called Autoruns. This program shows auto-start applications, Registry, and file system locations:

screenshot of autoruns application

manual malware removal step 2Restart your computer into Safe Mode:

Windows XP and Windows 7 users: Start your computer in Safe Mode. Click Start, click Shut Down, click Restart, click OK. During your computer start process, press the F8 key on your keyboard multiple times until you see the Windows Advanced Option menu, and then select Safe Mode with Networking from the list.

Safe Mode with Networking

Video showing how to start Windows 7 in "Safe Mode with Networking":

Windows 8 users: Start Windows 8 is Safe Mode with Networking - Go to Windows 8 Start Screen, type Advanced, in the search results select Settings. Click Advanced startup options, in the opened "General PC Settings" window, select Advanced startup. Click the "Restart now" button. Your computer will now restart into the "Advanced Startup options menu". Click the "Troubleshoot" button, and then click the "Advanced options" button. In the advanced option screen, click "Startup settings". Click the "Restart" button. Your PC will restart into the Startup Settings screen. Press F5 to boot in Safe Mode with Networking.

Windows 8 Safe Mode with networking

Video showing how to start Windows 8 in "Safe Mode with Networking":

Windows 10 users: Click the Windows logo and select the Power icon. In the opened menu click "Restart" while holding "Shift" button on your keyboard. In the "choose an option" window click on the "Troubleshoot", next select "Advanced options". In the advanced options menu select "Startup Settings" and click on the "Restart" button. In the following window you should click the "F5" button on your keyboard. This will restart your operating system in safe mode with networking.

windows 10 safe mode with networking

Video showing how to start Windows 10 in "Safe Mode with Networking":


manual malware removal step 3Extract the downloaded archive and run the Autoruns.exe file.

extract autoruns.zip and run autoruns.exe

manual malware removal step 4In the Autoruns application, click "Options" at the top and uncheck "Hide Empty Locations" and "Hide Windows Entries" options. After this procedure, click the "Refresh" icon.

Click 'Options' at the top and uncheck 'Hide Empty Locations' and 'Hide Windows Entries' options

manual malware removal step 5Check the list provided by the Autoruns application and locate the malware file that you want to eliminate.

You should write down its full path and name. Note that some malware hides process names under legitimate Windows process names. At this stage, it is very important to avoid removing system files. After you locate the suspicious program you wish to remove, right click your mouse over its name and choose "Delete".

locate the malware file you want to remove

After removing the malware through the Autoruns application (this ensures that the malware will not run automatically on the next system startup), you should search for the malware name on your computer. Be sure to enable hidden files and folders before proceeding. If you find the filename of the malware, be sure to remove it.

searching for malware file on your computer

Reboot your computer in normal mode. Following these steps should remove any malware from your computer. Note that manual threat removal requires advanced computer skills. If you do not have these skills, leave malware removal to antivirus and anti-malware programs. These steps might not work with advanced malware infections. As always it is best to prevent infection than try to remove malware later. To keep your computer safe, install the latest operating system updates and use antivirus software.

To be sure your computer is free of malware infections, we recommend scanning it with Malwarebytes for Windows.

About the author:

Tomas Meskauskas

Tomas Meskauskas - expert security researcher, professional malware analyst.

I am passionate about computer security and technology. I have an experience of over 10 years working in various companies related to computer technical issue solving and Internet security. I have been working as an author and editor for pcrisk.com since 2010. Follow me on Twitter and LinkedIn to stay informed about the latest online security threats. Contact Tomas Meskauskas.

PCrisk security portal is brought by a company RCS LT. Joined forces of security researchers help educate computer users about the latest online security threats. More information about the company RCS LT.

Our malware removal guides are free. However, if you want to support us you can send us a donation.

Malware activity

Global malware activity level today:

Medium threat activity

Increased attack rate of infections detected within the last 24 hours.

QR Code
GuLoader malware QR code
A QR code (Quick Response Code) is a machine-readable code which stores URLs and other information. This code can be read using a camera on a smartphone or a tablet. Scan this QR code to have an easy access removal guide of GuLoader malware on your mobile device.
We Recommend:

Get rid of Windows malware infections today:

Download Malwarebytes

Platform: Windows

Editors' Rating for Malwarebytes:
Editors ratingOutstanding!

[Back to Top]

To use full-featured product, you have to purchase a license for Malwarebytes. 14 days free trial available.