Trojan.ShellcodeRunner.FDF
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: | 80 % (High) |
| First Seen: | October 23, 2026 |
| Last Seen: | November 14, 2026 |
| OS(es) Affected: | Windows |
Trojan.ShellcodeRunner.FDF is a Windows Trojan with a danger level of 8 out of 10. It was first seen on 2026-10-23 and most recently on 2026-11-14, with 7 detections recorded in the feed. It has no digital signature. Trojans like this one pose as legitimate software and do their work quietly in the background.
Table of Contents
What the threat does
According to the feed, ShellcodeRunner.FDF installs itself stealthily and runs silently in the background while performing malicious functions. It may give attackers complete control over an infected system.
The name points to a shellcode loader. Programs of this kind typically load and run extra code directly in memory, which can then download or launch other malware. The feed does not confirm what payload this sample delivers, so treat that as typical behavior for the category.
Technical details from the feed:
- The file is a 64-bit native Windows GUI executable, not a .NET program, and it is not packed.
- It uses low-level system calls through ntdll.dll, including calls for writing files, freeing memory, and querying process information. Calling these functions directly is a technique typically used to avoid monitoring.
- It checks for a debugger using IsDebuggerPresent, a typical way for malware to hinder analysis.
- It reads user locale and user object information.
- It modified at least two files, a document-style file and a text file, in folders that resemble legitimate software locations.
The file's version information presents it as "Sciapisara Sync" or "Stuvo Toolkit", with matching company names and copyright text. This is a disguise. A professional-looking description does not make a file trustworthy, especially when it has no digital signature.
How it usually gets onto computers
The feed says this Trojan most often spreads by:
- Exploiting system vulnerabilities and security flaws.
- Software downloads from malicious websites.
- Email attachments from untrusted sources, usually .exe, .pif, .avi, and even .jpg files.
Fake installers and "free" tools are a typical delivery route for Trojans in general. The feed lists related families such as Injector.NGC and Trojan.Injector.Gen.KFL, which suggests similar code-injection behavior.
Risks for the user
Because the Trojan may give hackers full control of the system, the risks are serious. Typical consequences of this kind of access include:
- Theft of passwords, banking details, and personal files.
- Installation of additional malware, such as ransomware or spyware.
- Changes to or deletion of files.
- Use of the computer for further attacks.
The feed notes that the description of the threat's behavior continues beyond what is shown, so other harmful actions are possible.
Signs of infection
Trojans are designed to stay hidden, so there may be no obvious symptoms. Possible warning signs, typical for this category rather than confirmed for this sample, include:
- Unfamiliar programs, such as an unknown "Sync" or "Toolkit" application, that you did not install.
- Unexpected new or changed files in program or data folders.
- Slower performance or unexplained network activity.
- Security settings that change on their own.
- Accounts showing logins you do not recognize.
How to stay protected
- Keep Windows and all your software updated so that known vulnerabilities are patched.
- Download software only from the publisher's official website.
- Do not open attachments from unknown senders. Be cautious with executables and with images or videos that ask to be "run".
- Check the file type and digital signature of anything you download. A picture or video should never be an .exe or .pif file.
- Use a reputable, up-to-date anti-malware solution and run full scans regularly.
- Back up important files to a location that is not permanently connected to your computer.
If you suspect an infection, disconnect the computer from the internet, run a full system scan, and remove anything detected. Then change your important passwords from a clean device. If the machine was used for banking or work, consider also contacting the relevant providers.
Analysis Report
General information
| Family Name: | Trojan.ShellcodeRunner.FDF |
|---|---|
| Signature status: | No Signature |
Known Samples
Known Samples
This section lists other file samples believed to be associated with this family.|
MD5:
2a5dcdd46376d6ecf02ff98c6b1643b5
SHA1:
15d79c7a23b9870cc4f487199350101f3dbfa285
SHA256:
9005807048E97B49D5DEC776394E9EC9278881106E5ED3948E18A10E7D9655FC
File Size:
725.50 KB, 725504 bytes
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MD5:
0394213adacba9d39893e131bec6c552
SHA1:
89050434a74c0c43867e9c3c19d8811c5fd89dee
SHA256:
DC97435089FBE1F40A56C5D85A81BEA606DB55E735D415923A531D81B6780194
File Size:
700.93 KB, 700928 bytes
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Windows Portable Executable Attributes
- File doesn't have "Rich" header
- File doesn't have exports table
- File doesn't have security information
- File has TLS information
- 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)
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- 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 |
|---|---|
| Comments | Stuvo |
| Company Name |
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| File Description |
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| File Version |
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| Internal Name |
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| Legal Copyright |
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| Original Filename |
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| Product Name |
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| Product Version |
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File Traits
- HighEntropy
- ntdll
- 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: | 556 |
|---|---|
| Potentially Malicious Blocks: | 50 |
| Whitelisted Blocks: | 445 |
| Unknown Blocks: | 61 |
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.- Injector.NGC
- ShellcodeRunner.FDF
- Trojan.Injector.Gen.KFL
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:\program files (x86)\scary\eellaonk.pdf | Generic Write,Read Attributes |
| c:\programdata\mozilla firefox\szuenkeixooz.txt | Generic Write,Read 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 |
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| Anti Debug |
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| User Data Access |
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