Kaspersky Threats — Email-Worm.Win32.NetSky.b

Classe: Email-Worm

Email-Worms propagation par e-mail. Le ver envoie une copie de lui-même en pièce jointe à un message électronique ou un lien vers son fichier sur une ressource réseau (par exemple, une URL vers un fichier infecté sur un site Web compromis ou un site Web appartenant à un pirate). Dans le premier cas, le code du ver est activé lorsque la pièce jointe infectée est ouverte (lancée). Dans le second cas, le code est activé lorsque le lien vers le fichier infecté est ouvert. Dans les deux cas, le résultat est le même: le code du ver est activé. Email-Worms utilise une gamme de méthodes pour envoyer des emails infectés. Les plus courantes sont: l'utilisation d'une connexion directe à un serveur SMTP à l'aide du répertoire de messagerie intégré dans le code du ver en utilisant les services MS Outlook à l'aide des fonctions Windows MAPI. Email-Worms utilisent un certain nombre de sources différentes pour trouver les adresses email auxquelles les emails infectés seront envoyés: le carnet d'adresses dans MS Outlook une base de données d'adresses WAB .txt fichiers stockés sur le disque dur: le ver peut identifier les chaînes dans les fichiers texte Les e-mails adressent des e-mails dans la boîte de réception (certains e-mails peuvent même répondre aux e-mails trouvés dans la boîte de réception) De nombreux vers de messagerie utilisent plus d'une des sources répertoriées ci-dessus. Il existe également d'autres sources d'adresses électroniques, telles que les carnets d'adresses associés aux services de messagerie Web.

Plus d'informations

Plateforme: Win32

Win32 est une API sur les systèmes d'exploitation Windows NT (Windows XP, Windows 7, etc.) qui prend en charge l'exécution des applications 32 bits. L'une des plateformes de programmation les plus répandues au monde.

Famille: Email-Worm.Win32.NetSky

No family description

Examples

705AE748694FEB4FD13D6BC71A968433
C687E83D3B8FA1CADAD375854CE0A7E2
36568C2438EB4F126D2ED0EB6A90D4EE
6605C388EAA79B3FE9FC17EB69386811
CD72E9DB929BEDE3A1268B3987F6EBBF

Tactics and Techniques: Mitre*

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.

T1036.005

Match Legitimate Resource Name or Location

Adversaries may match or approximate the name or location of legitimate files, Registry keys, or other resources when naming/placing them. This is done for the sake of evading defenses and observation.

T1036.007

Double File Extension

Adversaries may abuse a double extension in the filename as a means of masquerading the true file type. A file name may include a secondary file type extension that may cause only the first extension to be displayed (ex: File.txt.exe may render in some views as just File.txt). However, the second extension is the true file type that determines how the file is opened and executed. The real file extension may be hidden by the operating system in the file browser (ex: explorer.exe), as well as in any software configured using or similar to the system’s policies.

T1112

Modify Registry

Adversaries may interact with the Windows Registry as part of a variety of other techniques to aid in defense evasion, persistence, and execution.

TA0006

Credential Access

The adversary is trying to steal account names and passwords. Credential Access consists of techniques for stealing credentials like account names and passwords. Techniques used to get credentials include keylogging or credential dumping. Using legitimate credentials can give adversaries access to systems, make them harder to detect, and provide the opportunity to create more accounts to help achieve their goals.

T1552.008

Chat Messages

Adversaries may directly collect unsecured credentials stored or passed through user communication services. Credentials may be sent and stored in user chat communication applications such as email, chat services like Slack or Teams, collaboration tools like Jira or Trello, and any other services that support user communication. Users may share various forms of credentials (such as usernames and passwords, API keys, or authentication tokens) on private or public corporate internal communications channels.

TA0010

Exfiltration

The adversary is trying to steal data. Exfiltration consists of techniques that adversaries may use to steal data from your network. Once they've collected data, adversaries often package it to avoid detection while removing it. This can include compression and encryption. Techniques for getting data out of a target network typically include transferring it over their command and control channel or an alternate channel and may also include putting size limits on the transmission.

T1048.003

Exfiltration Over Unencrypted Non-C2 Protocol

Adversaries may steal data by exfiltrating it over an un-encrypted network protocol other than that of the existing command and control channel. The data may also be sent to an alternate network location from the main command and control server.

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.

T1071.003

Mail Protocols

Adversaries may communicate using application layer protocols associated with electronic mail delivery to avoid detection/network filtering by blending in with existing traffic. Commands to the remote system, and often the results of those commands, will be embedded within the protocol traffic between the client and server.