Threat Database Trojans Trojan.CobaltStrike.O

Trojan.CobaltStrike.O

Threat Scorecard

Threat Level: 80 % (High)
Infected Computers: 19
First Seen: October 21, 2021
Last Seen: October 17, 2026
OS(es) Affected: Windows

Trojan.CobaltStrike.O is a dangerous Windows-based Trojan that belongs to a well-known family of threats associated with advanced attack tools. With a high danger rating, this threat is designed to give cybercriminals stealthy, remote access to an infected computer, putting both personal data and overall system security at serious risk.

What Trojan.CobaltStrike.O Does

Once active on a system, Trojan.CobaltStrike.O runs silently in the background, avoiding obvious signs of its presence. It is built to operate quietly for as long as possible, which allows attackers to carry out malicious activity without the user noticing anything unusual. The Trojan has no digital signature, meaning it has not been verified or certified as safe software, which is a common trait of malicious files.

Technically, the threat is a 64-bit executable that displays high entropy, a characteristic often associated with packed or obfuscated code designed to make analysis and detection more difficult. It lacks version information, debug data, and other standard metadata typically found in legitimate applications, further suggesting it was built to hide its true purpose. During operation, it has been observed creating communication channels, such as named pipes, that can be used to pass commands or data between processes, a technique frequently used by remote access tools to coordinate malicious activity. It also makes use of low-level system calls related to writing files, freeing memory, and managing system events, which can be leveraged to manipulate the infected machine behind the scenes.

Most importantly, Trojan.CobaltStrike.O may allow attackers to gain extensive, possibly complete, control over the infected system. This can include the ability to covertly delete files, install additional malicious software, and carry out other harmful commands remotely.

How It Usually Gets onto Computers

Like many threats in this category, Trojan.CobaltStrike.O typically spreads by exploiting system vulnerabilities and security flaws. It is often delivered through software downloads from malicious or compromised websites, as well as through email attachments sent from untrusted or unknown sources. These attachments can be disguised as seemingly harmless files, including executables and even image or video files, tricking users into opening them.

Risks for the User

Because this Trojan can give attackers remote control over a system, the risks are significant. Sensitive files could be stolen, altered, or deleted, additional malware could be installed without the user's knowledge, and the compromised machine could be used as a foothold for further attacks within a network. Given its stealthy design, victims may remain unaware of the compromise for an extended period, increasing the potential damage.

Signs of Infection

Because Trojans like this one are built to run silently, obvious symptoms may be minimal or absent. Users should be cautious of unexplained system slowdowns, unusual network activity, unfamiliar processes running in the background, or unexpected changes to files and settings. Since the Trojan lacks visible resources or interface elements, it may not display any windows or alerts at all.

How to Stay Protected

To reduce the risk of infection, users should keep their operating system and all installed software fully updated to close known security vulnerabilities. Avoid downloading software from untrusted or unofficial websites, and never open email attachments from unknown or unverified senders, especially executable files or files with unusual extensions. Maintaining regular backups of important data and using reputable, up-to-date security software to scan and monitor the system can also help detect and prevent threats like Trojan.CobaltStrike.O before they cause serious harm.

Analysis Report

General information

Family Name: Trojan.CobaltStrike.O
Signature status: No Signature

Known Samples

MD5: 095756b4f0e2e4ad22deed61d5930b53
SHA1: cd9a630ac8480a9bc6cabe62576a96729484d7ee
SHA256: 3C425CCC60A561DCFE942229EDACEF1BA18FF3F24362490663468B65DE15C9A8
File Size: 328.70 KB, 328704 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 relocations information
  • File doesn't have resources
  • 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)
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  • File is Native application (NOT .NET application)
  • File is not packed
  • IMAGE_FILE_DLL is not set inside PE header (Executable)
  • IMAGE_FILE_EXECUTABLE_IMAGE is set inside PE header (Executable Image)

File Traits

  • HighEntropy
  • No Version Info
  • x64

Block Information

Total Blocks: 123
Potentially Malicious Blocks: 7
Whitelisted Blocks: 116
Unknown Blocks: 0

Visual Map

0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 x x x 0 x x x 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 x
0 - Probable Safe Block
? - Unknown Block
x - Potentially Malicious Block

Similar Families

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  • Trojan.Kryptik.Gen.LIF
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  • Trojan.Metasploit.Gen.JE

Files Modified

File Attributes
\device\namedpipe\msse-3403-server Generic Write

Windows API Usage

Category API
Syscall Use
  • ntdll.dll!NtCreateNamedPipeFile
  • ntdll.dll!NtFreeVirtualMemory
  • ntdll.dll!NtQueryInformationThread
  • ntdll.dll!NtQueryInformationToken
  • ntdll.dll!NtSetEvent
  • ntdll.dll!NtSetInformationWorkerFactory
  • ntdll.dll!NtTestAlert
  • ntdll.dll!NtWaitLowEventPair
  • ntdll.dll!NtWriteFile
  • UNKNOWN