Trojan.Downloader.Agent.NAU
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.
| Popularity Rank: | 15,408 |
| Threat Level: | 80 % (High) |
| Infected Computers: | 18 |
| First Seen: | February 8, 2024 |
| Last Seen: | October 9, 2026 |
| OS(es) Affected: | Windows |
Trojan.Downloader.Agent.NAU is a malicious Windows program classified as a Trojan downloader. Its main purpose is not to cause visible damage by itself, but to quietly open the door for other malware by downloading and installing additional malicious components onto an infected computer. First observed in February 2024 and still being detected, this threat carries a high danger rating due to its ability to act as a launching pad for much more damaging infections.
Table of Contents
What Trojan.Downloader.Agent.NAU Does
Once active on a system, Trojan.Downloader.Agent.NAU runs silently in the background, hiding its presence from the user. It is designed to stealth-install itself and then carry out malicious functions without any visible signs of activity. Analysis of its behavior shows that it can launch the Windows PowerShell tool with hidden windows and bypassed execution policies, allowing it to run scripts and commands without triggering normal security prompts. It also interacts with system processes, checks for the presence of debugging tools, and gathers information about the logged-in user, such as the username and locale settings. These capabilities suggest the Trojan is built to operate covertly while preparing the system for further compromise, such as downloading additional payloads, allowing remote attackers to gain control, or harvesting sensitive data.
How It Usually Gets onto Computers
Trojan.Downloader.Agent.NAU typically spreads by exploiting system vulnerabilities and security weaknesses. It is commonly bundled with software downloaded from untrustworthy or malicious websites, or delivered through email attachments from unknown or suspicious senders. These attachments can be disguised as ordinary files, including executables, media files, or even image files, tricking users into opening them. As is typical for downloader-type Trojans, infection often happens without any obvious warning, since the malicious file may look harmless at first glance.
Risks for the User
Because this Trojan is primarily a downloader, its biggest risk is what it can bring onto the system afterward. It may allow hackers to gain extensive control over the infected computer, potentially leading to the installation of spyware, ransomware, password stealers, or other dangerous programs. Its use of hidden PowerShell commands and privilege-related system calls indicates it can attempt to escalate its access and perform actions that are difficult for an average user to detect. Left unaddressed, this can result in stolen credentials, financial loss, corrupted files, or a severely compromised system.
Signs of Infection
Because Trojan.Downloader.Agent.NAU is designed to run quietly, obvious symptoms may be minimal. However, users should watch for unexplained slowdowns, unusual background processes, unexpected PowerShell windows briefly appearing, spikes in network activity, or new and unfamiliar files appearing in temporary folders. Security software flagging suspicious scripts or detecting this specific Trojan name is often the clearest indicator of infection.
How to Stay Protected
To reduce the risk of infection, avoid downloading software from unofficial or unverified websites, and never open email attachments from unknown or unexpected senders, especially executable files or files with unusual extensions. Keep the Windows operating system and all installed software fully updated, since this Trojan relies on exploiting unpatched vulnerabilities. Regularly back up important files, use caution when enabling macros or running scripts, and keep a reputable, up-to-date security solution active to detect and block threats like Trojan.Downloader.Agent.NAU before they can cause harm.
Analysis Report
General information
| Family Name: | Trojan.Downloader.Agent.NAU |
|---|---|
| Signature status: | No Signature |
Known Samples
Known Samples
This section lists other file samples believed to be associated with this family.|
MD5:
48f1316432f4b9714542cf733d936ed8
SHA1:
34917dad9f0977a1d3e8d7228b60246615bc28dd
SHA256:
BA2FE025F1D1EEE75D547CE5BE1340A09FFEB83F35883D367B4095FFCA60C257
File Size:
135.17 KB, 135168 bytes
|
Windows Portable Executable Attributes
- File doesn't have "Rich" header
- File doesn't have resources
- File doesn't have security information
- File has exports table
- File is 64-bit executable
- File is either console or GUI application
- File is GUI application (IMAGE_SUBSYSTEM_WINDOWS_GUI)
- File is Native application (NOT .NET application)
- File is not packed
- IMAGE_FILE_DLL is not set inside PE header (Executable)
Show 1 more
- IMAGE_FILE_EXECUTABLE_IMAGE is set inside PE header (Executable Image)
File Traits
- dll
- x64
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: | 478 |
|---|---|
| Potentially Malicious Blocks: | 16 |
| Whitelisted Blocks: | 461 |
| Unknown Blocks: | 1 |
Visual Map
? - Unknown Block
x - Potentially Malicious Block
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 |
|---|---|
| \device\namedpipe\dav rpc service | Generic Read,Write Data,Write Attributes,Write extended,Append data |
| \device\namedpipe\pshost.134330117538528711.4124.defaultappdomain.powershell | Generic Read,Write Data,Write Attributes,Write extended,Append data,LEFT 524288 |
| \device\namedpipe\wkssvc | Generic Read,Write Data,Write Attributes,Write extended,Append data |
| c:\users\user\appdata\local\temp\__psscriptpolicytest_5ho5pj4z.44r.psm1 | Generic Write,Read Attributes |
| c:\users\user\appdata\local\temp\__psscriptpolicytest_oih24goz.lbn.ps1 | Generic Write,Read Attributes |
Registry Modifications
Registry Modifications
This section lists registry keys and values that were created, modified and/or deleted by samples in this family. Windows Registry activity can provide valuable insight into malware functionality. Additionally, malware often creates registry values to allow itself to automatically start and indefinitely persist after an initial infection has compromised the system.| Key::Value | Data | API Name |
|---|---|---|
| HKLM\system\controlset001\services\bam\state\usersettings\s-1-5-21-3119368278-1123331430-659265220-1001::\device\harddiskvolume2\windows\system32\cmd.exe | 멁㲇ǝ | RegNtPreCreateKey |
| HKLM\system\controlset001\services\bam\state\usersettings\s-1-5-21-3119368278-1123331430-659265220-1001::\device\harddiskvolume2\windows\system32\conhost.exe | ᏽ멉㲇ǝ | RegNtPreCreateKey |
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 90 more
26 additional items are not displayed above. |
| Anti Debug |
|
| User Data Access |
|
| Process Shell Execute |
|
| Encryption Used |
|
| Other Suspicious |
|
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\System32\WindowsPowerShell\v1.0\powershell.exe powershell.exe -windowstyle hidden -NoProfile -ExecutionPolicy bypass -Command $mydir = [System.Environment]::GetFolderPath('CommonApplicationData')
|
