Backdoor.MSIL.Agent.FBK
Threat Scorecard
EnigmaSoft Threat Scorecard
EnigmaSoft Threat Scorecards are assessment reports for different malware threats which have been collected and analyzed by our research team. EnigmaSoft Threat Scorecards evaluate and rank threats using several metrics including real-world and potential risk factors, trends, frequency, prevalence, and persistence. EnigmaSoft Threat Scorecards are updated regularly based on our research data and metrics and are useful for a wide range of computer users, from end users seeking solutions to remove malware from their systems to security experts analyzing threats.
EnigmaSoft Threat Scorecards display a variety of useful information, including:
Popularity Rank: The ranking of a particular threat in EnigmaSoft’s Threat Database.
Severity Level: The determined severity level of an object, represented numerically, based on our risk modeling process and research, as explained in our Threat Assessment Criteria.
Infected Computers: The number of confirmed and suspected cases of a particular threat detected on infected computers as reported by SpyHunter.
See also Threat Assessment Criteria.
| Threat Level: | 60 % (Medium) |
| Infected Computers: | 3 |
| First Seen: | July 28, 2025 |
| Last Seen: | November 30, 2025 |
| OS(es) Affected: | Windows |
The detection of Backdoor.MSIL.Agent.FBK on your system indicates a potential security threat that requires immediate attention. This backdoor threat can compromise the security and integrity of your computer, allowing unauthorized access and potentially leading to further malicious activities. It is essential to understand the nature of this threat and take prompt action to remove it and secure your system.
Table of Contents
What Is Backdoor.MSIL.Agent.FBK?
Backdoor.MSIL.Agent.FBK is a type of backdoor threat that can create a covert communication channel between your computer and a remote server controlled by an attacker. This allows the attacker to access your system without your knowledge or consent, potentially leading to data theft, system compromise, or the installation of additional malware. The name suggests it is written in MSIL (Microsoft Intermediate Language), which is a platform-agnostic intermediate representation of the .NET Common Intermediate Language (CIL).
How Backdoor.MSIL.Agent.FBK Operates
Backdoor threats like Backdoor.MSIL.Agent.FBK typically operate by exploiting vulnerabilities in software or using social engineering tactics to trick users into installing them. Once installed, they can communicate with their command and control (C2) servers to receive instructions, which can include downloading and installing additional malware, stealing sensitive information, or using the compromised system for malicious activities such as spamming or participating in botnet attacks.
Symptoms of Infection
Symptoms of a Backdoor.MSIL.Agent.FBK infection can be subtle and may not always be immediately apparent. However, signs of infection can include unusual network activity, slow system performance, unexpected changes to system settings, or the appearance of unfamiliar programs or icons. If you suspect your system has been infected, it is crucial to take immediate action to mitigate the threat.
How to Remove Backdoor.MSIL.Agent.FBK
- Boot your computer in Safe Mode with Networking to prevent the malware from loading and to allow for a cleaner environment to perform removal steps.
- Use a reputable anti-malware tool, such as SpyHunter, to perform a full scan of your system. This can help identify and remove the backdoor threat and any associated malware.
- Uninstall any suspicious programs or applications that you do not recognize or that were installed around the time of the suspected infection.
- Reset your web browsers (Chrome, Firefox, Edge, etc.) to their default settings to remove any malicious extensions or settings changes made by the malware.
- Reboot your system and perform another full scan with your anti-malware tool to ensure that the threat has been fully removed.
Conclusion
Removing Backdoor.MSIL.Agent.FBK requires careful and immediate action to prevent further system compromise and potential data loss. By following the steps outlined above and maintaining good security practices, such as keeping your operating system and software up to date, using strong antivirus software, and being cautious with emails and downloads, you can help protect your system from similar threats in the future. Regularly scanning your system for malware and being vigilant for signs of infection are key components of a robust security strategy.
Analysis Report
General information
| Family Name: | Backdoor.MSIL.Agent.FBK |
|---|---|
| Signature status: | No Signature |
Known Samples
Known Samples
This section lists other file samples believed to be associated with this family.|
MD5:
7e16aeab737c35d72fd2c75294ee40d9
SHA1:
fcfa480d9821d158a3d1e5b7ad9f8789129d372d
SHA256:
35A6FD0302BD10FE151825FF87BFA237D3015E71FE3BD9D51F1E2ECB362B925C
File Size:
88.06 KB, 88064 bytes
|
|
MD5:
81a51be1d2ecaa472d76393477b7d12c
SHA1:
35c3681ba36363ff849468c00ca0b4833e4c7bf1
SHA256:
75C34963CC931355215F4E5D8FAA9984DB14793306C250017A5138EC58F28532
File Size:
125.95 KB, 125952 bytes
|
Windows Portable Executable Attributes
- File doesn't have "Rich" header
- File doesn't have debug information
- File doesn't have exports table
- File doesn't have security information
- File is .NET application
- File is 32-bit executable
- File is either console or GUI application
- File is GUI application (IMAGE_SUBSYSTEM_WINDOWS_GUI)
- File is not packed
- IMAGE_FILE_DLL is not set inside PE header (Executable)
Show More
- IMAGE_FILE_EXECUTABLE_IMAGE is set inside PE header (Executable Image)
File Icons
File Icons
This section displays icon resources found within family samples. Malware often replicates icons commonly associated with legitimate software to mislead users into believing the malware is safe.
Windows PE Version Information
Windows PE Version Information
This section displays values and attributes that have been set in the Windows file version information data structure for samples within this family. To mislead users, malware actors often add fake version information mimicking legitimate software.| Name | Value |
|---|---|
| Assembly Version | 1.0.0.0 |
| Company Name | Microsoft Corporation |
| File Description |
|
| File Version |
|
| Internal Name |
|
| Legal Copyright |
|
| Original Filename |
|
| Product Name |
|
| Product Version |
|
File Traits
- .NET
- RijndaelManaged
- WriteProcessMemory
- x86
Block Information
Block Information
During analysis, EnigmaSoft breaks file samples into logical blocks for classification and comparison with other samples. Blocks can be used to generate malware detection rules and to group file samples into families based on shared source code, functionality and other distinguishing attributes and characteristics. This section lists a summary of this block data, as well as its classification by EnigmaSoft. A visual representation of the block data is also displayed, where available.| Total Blocks: | 92 |
|---|---|
| Potentially Malicious Blocks: | 3 |
| Whitelisted Blocks: | 70 |
| Unknown Blocks: | 19 |
Visual Map
? - Unknown Block
x - Potentially Malicious Block
Similar Families
Similar Families
This section lists other families that share similarities with this family, based on EnigmaSoft’s analysis. Many malware families are created from the same malware toolkits and use the same packing and encryption techniques but uniquely extend functionality. Similar families may also share source code, attributes, icons, subcomponents, compromised and/or invalid digital signatures, and network characteristics. Researchers leverage these similarities to rapidly and effectively triage file samples and extend malware detection rules.- MSIL.Agent.DFDF
- MSIL.Agent.FBK
- MSIL.Agent.PI
- MSIL.Bladabindi.R
- MSIL.Gamehack.BOWB
Show More
- MSIL.Gamehack.BOWD
- MSIL.Krypt.FHH
- MSIL.Krypt.YEK
- MSIL.Kryptik.FHE
- MSIL.Kryptik.FHM
- MSIL.Njrat.J
- MSIL.Spy.Agent.GAE
Files Modified
Files Modified
This section lists files that were created, modified, moved and/or deleted by samples in this family. File system activity can provide valuable insight into how malware functions on the operating system.| File | Attributes |
|---|---|
| c:\windows\appcompat\programs\amcache.hve | Read Data,Read Control,Write Data |
| c:\windows\appcompat\programs\amcache.hve | Write Attributes |
Windows API Usage
Windows API Usage
This section lists Windows API calls that are used by the samples in this family. Windows API usage analysis is a valuable tool that can help identify malicious activity, such as keylogging, security privilege escalation, data encryption, data exfiltration, interference with antivirus software, and network request manipulation.| Category | API |
|---|---|
| Syscall Use |
Show More
|
| User Data Access |
|
| Process Manipulation Evasion |
|
| Anti Debug |
|
| Process Shell Execute |
|
| Encryption Used |
|
Shell Command Execution
Shell Command Execution
This section lists Windows shell commands that are run by the samples in this family. Windows Shell commands are often leveraged by malware for nefarious purposes and can be used to elevate security privileges, download and launch other malware, exploit vulnerabilities, collect and exfiltrate data, and hide malicious activity.
C:\Windows\Microsoft.NET\Framework64\v2.0.50727\\dw20.exe dw20.exe -x -s 696
|
