Trojan.Kryptik.FRS
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: | 15,379 |
| Threat Level: | 80 % (High) |
| Infected Computers: | 5 |
| First Seen: | March 12, 2026 |
| Last Seen: | July 11, 2026 |
| OS(es) Affected: | Windows |
Trojan.Kryptik.FRS is a heuristic detection assigned to a heavily obfuscated 64-bit Windows executable that antivirus engines cannot confidently tie to a single named malware family. The "Kryptik" label is one of the industry's oldest and most widely used generic classifications for cryptor-protected trojans, and the .FRS suffix simply identifies the specific obfuscation cluster this sample falls into.
Because Trojan.Kryptik.FRS describes how a file is hidden rather than what it ultimately does, files carrying this detection can turn out to be information stealers, backdoors, downloaders, or loader components for later-stage payloads. This report walks through the real characteristics of the analyzed sample, explains what a Kryptik detection means, and provides complete removal guidance.
Table of Contents
What Is Trojan.Kryptik.FRS?
Trojan.Kryptik.FRS is a member of the broad Trojan Kryptik detection family, a generic, heuristic signature most closely associated with ESET's long-running "Win32/Kryptik" and "Win64/Kryptik" classifications. Kryptik first appeared in the wild around 2008 and has remained in continuous use ever since, not because it is a single piece of code, but because it captures a shared trait: the sample has been run through a cryptor or packer that scrambles its true logic to defeat signature-based scanning.
Critically, a Kryptik detection is a statement about camouflage, not about capability. Two files both flagged as Kryptik may share almost nothing at the payload level. For that reason this article frames its analysis around the concrete, observed properties of the specific sample rather than claiming a definitive end-goal. The analyzed file is a 64-bit executable compiled from Go (Golang), a language increasingly favored by malware authors because its large statically linked runtime bloats the binary, buries malicious routines among legitimate runtime code, and complicates reverse engineering across platforms.
How It Spreads / Distribution
Kryptik-classified trojans do not rely on a single delivery mechanism; they are distributed through whatever channel the operator behind a given campaign prefers. Based on well-documented public reporting on Kryptik-family activity, the most common vectors are phishing emails carrying malicious attachments or links, drive-by downloads from compromised or malicious websites, and exploit kits that target unpatched software. Social engineering is the connective tissue: victims are persuaded to open a document, run an installer, or click a link that launches the obfuscated payload.
Secondary distribution routes frequently include cracked or "free" software bundles, fake updates, malicious advertising, and pay-per-install loader services that push cryptor-wrapped binaries to already-compromised machines. Because the outer cryptor is regenerated for each build, the same underlying threat can appear as a fresh, previously unseen file on every victim, which is precisely why heuristic labels like Kryptik exist.
Technical Analysis & Behavior
In the sandbox detonation of this sample, the automated analysis engine surfaced direct system-call usage as the primary behavioral category. Direct syscalls are a deliberate evasion technique: instead of calling documented Windows API functions through the usual libraries, the malware invokes kernel services directly, bypassing user-mode hooks that endpoint-detection products place on standard API entry points. This is consistent with a sample engineered to slip past behavioral monitoring.
The file is a Golang, x64 binary weighing 2,195,456 bytes (roughly 2.09 MB). No conventional packer signature was identified, which is typical of Go malware: the language's own runtime and its statically compiled structure already provide substantial obfuscation and inflate the file, so authors often skip a separate packing stage. The portable-executable header showed multiple characteristic flags set (a PE-flag count of 11), reflecting the atypical section layout and metadata that Go and its evasion tooling produce.
During this particular run the engine recorded zero registry modifications and zero file-system modifications. That absence should not be read as "harmless." It commonly indicates a sample that stalled, detected the analysis environment, waited on a trigger, or gated its malicious routines behind conditions (network connectivity, a command signal, or a specific host profile) that were not met inside the sandbox window. Combined with direct-syscall behavior, the profile is that of an evasion-focused loader or stager.
Indicators of Compromise
The following indicators come from the single analyzed sample. Values reflect one analyzed sample; specific indicators rotate as operators repack and rebuild, so these hashes identify this exact file and should be treated as one data point rather than a durable family signature.
- SHA-256: 1e81a8bbfd70426367039e57fa9c82130c05bd5139866c40f0f33ed68d84f907
- SHA-1: 0d60f7ee46aaebacb108a7b4ddff6ed5ec6686cc
- MD5: ba90d0b41689c81ad2071f8d1530c4eb
- File size: 2,195,456 bytes (~2.09 MB)
- File type / traits: 64-bit (x64) Windows PE compiled from Golang
- Digital signature: unsigned / no valid Authenticode signer present
The sample carries no valid code-signing certificate, which is itself a soft indicator: a legitimate 2 MB application binary would typically be signed by a recognizable publisher. No network indicators, first-seen dates, or geographic telemetry are asserted here because none were present in the underlying analysis data.
Detection Heuristics
Antivirus engines flag Trojan.Kryptik.FRS through heuristic and machine-learning models rather than a fixed byte signature, precisely because the outer layer changes with every build. The analyzed file's nearest-neighbor scoring placed it closest to other obfuscation clusters in the same ecosystem, most strongly Kryptik.GDSY (~75% similarity), followed by Agent.MYS (~72%), Kryptik.BFSC (~71%), Kryptik.FRS (~70%), Agent.BSA (~61%), and MSIL.Brute.TT (~59%). Those neighbors are themselves generic cryptor/agent labels, reinforcing that the detection is anchored on obfuscation structure, not a specific payload.
Practical heuristics that raise the flag include: an unsigned Go-compiled x64 executable of a few megabytes; anomalous PE section characteristics; the use of direct system calls to bypass API hooks; and behavioral models that recognize the "quiet then triggered" execution pattern common to evasive loaders. Static-only scanning is weak against these files, which is why layered behavioral detection matters.
Digital Forensics
Investigators triaging a suspected Trojan.Kryptik.FRS infection should hunt for the artifacts below. Note that in this sample's controlled run the engine logged zero persisted registry keys and zero written files, so on a live host the malicious artifacts may only appear after the sample's trigger conditions are satisfied.
- Files: search for an unsigned ~2.09 MB x64 executable matching the hashes above, and for Go-compiled binaries in user-writable locations such as %TEMP%, %APPDATA%, %LOCALAPPDATA%, and the user's Downloads folder.
- Processes: look for an unsigned executable making direct syscalls, spawning unexpected child processes, or running from a temporary directory.
- Registry: although this run showed no registry writes, standard persistence locations still warrant review — Run/RunOnce keys, scheduled-task registrations, and service entries created around the time of first execution.
- Persistence & execution: examine scheduled tasks, autostart entries, and recently created services, correlating timestamps with the appearance of the suspicious binary.
Because the underlying payload class is uncertain, a full memory capture and network-traffic review are recommended to determine whether the loader retrieved and executed a later-stage component.
Symptoms of Infection
Symptoms vary with whatever payload the cryptor ultimately delivers, but common signs of a Kryptik-class compromise include: noticeable system slowdowns and unexplained CPU or network activity; an unfamiliar process running from a temporary folder; security software being disabled, crashing, or unable to update; unexpected outbound connections; browser redirects or new toolbars if the payload is adware- or stealer-oriented; and, in stealer scenarios, evidence of credential theft such as unexpected account logins. In many cases there are no obvious symptoms at all, since evasive loaders are designed to run silently.
How to Remove Trojan.Kryptik.FRS
Because the payload behind a Kryptik detection is unpredictable, prompt and thorough removal is important.
1. Run a full anti-malware scan. Use a reputable, up-to-date security tool such as SpyHunter to perform a complete system scan. Because Trojan.Kryptik.FRS is designed to evade static detection, a behavioral, full-disk scan is far more effective than a quick scan. Allow the tool to quarantine or remove every flagged item, then reboot and re-scan to confirm the system is clean.
2. Boot into Safe Mode with Networking if the threat resists removal or interferes with your security software. Restart Windows into Safe Mode, then run the full scan again so the malware's evasion routines and any triggered components are less likely to load.
3. Clean affected web browsers. If you notice redirects, pop-ups, or unwanted extensions, reset each browser:
- Google Chrome: Settings > Extensions > remove anything unfamiliar, then Settings > Reset settings > Restore settings to their original defaults.
- Mozilla Firefox: Add-ons and themes > Extensions > remove suspicious entries, then Help > More troubleshooting information > Refresh Firefox.
- Microsoft Edge: Extensions > remove unknown add-ons, then Settings > Reset settings > Restore settings to their default values.
- Android: uninstall recently added or unknown apps, clear the affected browser app's cache and data, and run a mobile security scan; reboot into Android Safe Mode if an app cannot be removed normally.
4. Manual cleanup (advanced users). Terminate any suspicious unsigned process, delete the offending executable and any Go-compiled binaries dropped in %TEMP%, %APPDATA%, or %LOCALAPPDATA%, and remove any newly created autostart entries, scheduled tasks, or services. Use the hashes in the Indicators of Compromise section to identify the exact file.
5. Post-removal hardening. Change important passwords from a known-clean device (in case a stealer payload was active), apply all operating-system and application updates, and keep real-time protection enabled going forward.
Conclusion
Trojan.Kryptik.FRS is best understood as a warning that a file has been deliberately obfuscated to hide its purpose, not as a verdict on a specific malware family. The analyzed sample — an unsigned, 2.09 MB Golang x64 executable that leans on direct system calls to evade monitoring — fits the profile of an evasion-focused trojan or loader whose ultimate payload can vary from campaign to campaign. Given that uncertainty, any file flagged as Trojan.Kryptik.FRS should be treated as hostile and removed promptly with a full, behavior-aware security scan, followed by credential hygiene and system patching to close the door behind it.
Analysis Report
General information
| Family Name: | Trojan.Kryptik.FRS |
|---|---|
| Signature status: | No Signature |
Known Samples
Known Samples
This section lists other file samples believed to be associated with this family.|
MD5:
ba90d0b41689c81ad2071f8d1530c4eb
SHA1:
0d60f7ee46aaebacb108a7b4ddff6ed5ec6686cc
SHA256:
1E81A8BBFD70426367039E57FA9C82130C05BD5139866C40F0F33ED68D84F907
File Size:
2.20 MB, 2195456 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 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)
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 |
|---|---|
| Company Name | certificates |
| File Version | 1.0.0.0 |
| Internal Name | certificates |
| Legal Copyright | certificates |
| Original Filename | certificates.exe |
| Product Name | certificates |
| Product Version | 1.0.0.0 |
File Traits
- golang
- 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: | 3,010 |
|---|---|
| Potentially Malicious Blocks: | 108 |
| Whitelisted Blocks: | 2,446 |
| Unknown Blocks: | 456 |
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.- Agent.BSA
- Agent.MYS
- Kryptik.BFSC
- Kryptik.FRS
- Kryptik.GDSY
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- MSIL.Brute.TT
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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