Kaspersky Threats — Backdoor.Win32.Crysan.anx

Třída: Backdoor

Zadní stěny jsou navrženy tak, aby poskytovaly škodlivým uživatelům vzdálený přístup k infikovanému počítači. Pokud jde o funkčnost, Backdoors jsou podobné mnoha administrativním systémům navrženým a distribuovaným vývojáři softwaru.

Tyto typy škodlivých programů umožňují dělat cokoliv, co autor chce na napadeném počítači: odesílat a přijímat soubory, spouštět soubory nebo je smazat, zobrazovat zprávy, mazat data, restartovat počítač atd.

Programy v této kategorii se často používají k sjednocení skupiny obětí počítačů a vytvoření sítě botnet nebo zombie. To dává zlomyslným uživatelům centralizovanou kontrolu nad armádou infikovaných počítačů, které pak mohou být použity pro kriminální účely.

Existuje také skupina Backdoors, která je schopna šíření prostřednictvím sítí a infikování jiných počítačů jako Net-Worms. Rozdíl je v tom, že takové Backdoors se nerozšířují automaticky (jak to dělá Net-Worms), ale pouze na speciální "příkaz" od škodlivého uživatele, který je ovládá.

Platfoma: Win32

Win32 je rozhraní API v operačních systémech Windows NT (Windows XP, Windows 7 atd.), Které podporují provádění 32bitových aplikací. Jedna z nejrozšířenějších programovacích platforem na světě.

Family: Backdoor.Win32.Crysan

No family description

Examples

2FC462B68E5D4C635296F7E260A22789

Tactics and Techniques: Mitre*

TA0002

Execution

The adversary is trying to run malicious code. Execution consists of techniques that result in adversary-controlled code running on a local or remote system. Techniques that run malicious code are often paired with techniques from all other tactics to achieve broader goals, like exploring a network or stealing data. For example, an adversary might use a remote access tool to run a PowerShell script that does Remote System Discovery.

T1059.001

PowerShell

Adversaries may abuse PowerShell commands and scripts for execution. PowerShell is a powerful interactive command-line interface and scripting environment included in the Windows operating system. Adversaries can use PowerShell to perform a number of actions, including discovery of information and execution of code. Examples include the Start-Process cmdlet which can be used to run an executable and the Invoke-Command cmdlet which runs a command locally or on a remote computer (though administrator permissions are required to use PowerShell to connect to remote systems).

T1059.005

Visual Basic

Adversaries may abuse Visual Basic (VB) for execution. VB is a programming language created by Microsoft with interoperability with many Windows technologies such as Component Object Model and the Native API through the Windows API. Although tagged as legacy with no planned future evolutions, VB is integrated and supported in the .NET Framework and cross-platform .NET Core.

T1204.002

Malicious File

An adversary may rely upon a user opening a malicious file in order to gain execution. Users may be subjected to social engineering to get them to open a file that will lead to code execution. This user action will typically be observed as follow-on behavior from Spearphishing Attachment. Adversaries may use several types of files that require a user to execute them, including .doc, .pdf, .xls, .rtf, .scr, .exe, .lnk, .pif, and .cpl.

TA0003

Persistence

The adversary is trying to maintain their foothold. Persistence consists of techniques that adversaries use to keep access to systems across restarts, changed credentials, and other interruptions that could cut off their access. Techniques used for persistence include any access, action, or configuration changes that let them maintain their foothold on systems, such as replacing or hijacking legitimate code or adding startup code.

T1547.001

Registry Run Keys / Startup Folder

Adversaries may achieve persistence by adding a program to a startup folder or referencing it with a Registry run key. Adding an entry to the "run keys" in the Registry or startup folder will cause the program referenced to be executed when a user logs in. These programs will be executed under the context of the user and will have the account's associated permissions level.

TA0004

Privilege Escalation

The adversary is trying to gain higher-level permissions. Privilege Escalation consists of techniques that adversaries use to gain higher-level permissions on a system or network. Adversaries can often enter and explore a network with unprivileged access but require elevated permissions to follow through on their objectives. Common approaches are to take advantage of system weaknesses, misconfigurations, and vulnerabilities. Examples of elevated access include: SYSTEM/root level, local administrator, user account with admin-like access, user accounts with access to specific system or perform specific function. These techniques often overlap with Persistence techniques, as OS features that let an adversary persist can execute in an elevated context.

T1547.001

Registry Run Keys / Startup Folder

TA0005

Defense Evasion

The adversary is trying to avoid being detected. Defense Evasion consists of techniques that adversaries use to avoid detection throughout their compromise. Techniques used for defense evasion include uninstalling/disabling security software or obfuscating/encrypting data and scripts. Adversaries also leverage and abuse trusted processes to hide and masquerade their malware. Other tactics' techniques are cross-listed here when those techniques include the added benefit of subverting defenses.

T1112

Modify Registry

Adversaries may interact with the Windows Registry to hide configuration information within Registry keys, remove information as part of cleaning up, or as part of other techniques to aid in persistence and execution.

TA0011

Command and Control

The adversary is trying to communicate with compromised systems to control them. Command and Control consists of techniques that adversaries may use to communicate with systems under their control within a victim network. Adversaries commonly attempt to mimic normal, expected traffic to avoid detection. There are many ways an adversary can establish command and control with various levels of stealth depending on the victim's network structure and defenses.

T1095

Non-Application Layer Protocol

Adversaries may use an OSI non-application layer protocol for communication between host and C2 server or among infected hosts within a network. The list of possible protocols is extensive. Specific examples include use of network layer protocols, such as the Internet Control Message Protocol (ICMP), transport layer protocols, such as the User Datagram Protocol (UDP), session layer protocols, such as Socket Secure (SOCKS), as well as redirected/tunneled protocols, such as Serial over LAN (SOL).

T1105

Ingress Tool Transfer

Adversaries may transfer tools or other files from an external system into a compromised environment. Tools or files may be copied from an external adversary-controlled system to the victim network through the command and control channel or through alternate protocols such as ftp. Once present, adversaries may also transfer/spread tools between victim devices within a compromised environment (i.e. Lateral Tool Transfer).