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

Kategorie: Email-Worm

E-Mail-Würmer verbreiten sich per E-Mail. Der Wurm sendet eine Kopie von sich selbst als Anhang an eine E-Mail-Nachricht oder einen Link zu seiner Datei auf einer Netzwerkressource (z. B. eine URL zu einer infizierten Datei auf einer kompromittierten Website oder einer Hacker-eigenen Website).

Im ersten Fall wird der Wurmcode aktiviert, wenn der infizierte Anhang geöffnet (gestartet) wird. Im zweiten Fall wird der Code aktiviert, wenn der Link zur infizierten Datei geöffnet wird. In beiden Fällen ist das Ergebnis dasselbe: Der Wurmcode ist aktiviert.

Email-Würmer verwenden eine Reihe von Methoden, um infizierte E-Mails zu versenden. Die häufigsten sind:

Verwenden einer direkten Verbindung zu einem SMTP-Server mithilfe des E-Mail-Verzeichnisses, das in den Code des Wurms integriert ist
Verwenden von MS Outlook-Diensten
Verwenden von Windows MAPI-Funktionen.
Email-Würmer verwenden eine Reihe verschiedener Quellen, um E-Mail-Adressen zu finden, an die infizierte E-Mails gesendet werden:

das Adressbuch in MS Outlook
eine WAB-Adressdatenbank
.txt-Dateien, die auf der Festplatte gespeichert sind: Der Wurm kann feststellen, welche Zeichenfolgen in Textdateien E-Mail-Adressen sind
E-Mails im Posteingang (einige E-Mail-Würmer "antworten" sogar auf E-Mails im Posteingang)
Viele E-Mail-Würmer verwenden mehr als eine der oben aufgeführten Quellen. Es gibt auch andere Quellen für E-Mail-Adressen, z. B. Adressbücher für webbasierte E-Mail-Dienste.

Mehr Informationen

Plattform: Win32

Win32 ist eine API auf Windows NT-basierten Betriebssystemen (Windows XP, Windows 7 usw.), die die Ausführung von 32-Bit-Anwendungen unterstützt. Eine der am weitesten verbreiteten Programmierplattformen der Welt.

Familie: Email-Worm.Win32.Tanatos

No family description

Examples

5AAAC8D190B11996BB8BD31F5C9E7263
D99CD74D769BE9A9401676BFD86D09BF
0F91DA66D1A0382ADF4172BC9EFC6D24
41CBFB865F59F61794FFE606688FD0BE
BAF58A2317DB6B30969EA4B1B1E48F0B

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.

T1106

Native API

Adversaries may interact with the native OS application programming interface (API) to execute behaviors. Native APIs provide a controlled means of calling low-level OS services within the kernel, such as those involving hardware/devices, memory, and processes. These native APIs are leveraged by the OS during system boot (when other system components are not yet initialized) as well as carrying out tasks and requests during routine operations.

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.

T1055

Process Injection

Adversaries may inject code into processes in order to evade process-based defenses as well as possibly elevate privileges. Process injection is a method of executing arbitrary code in the address space of a separate live process. Running code in the context of another process may allow access to the process's memory, system/network resources, and possibly elevated privileges. Execution via process injection may also evade detection from security products since the execution is masked under a legitimate process.

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.

T1036.007

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.

T1036.008

Masquerade File Type

Adversaries may masquerade malicious payloads as legitimate files through changes to the payload's formatting, including the file’s signature, extension, icon, and contents. Various file types have a typical standard format, including how they are encoded and organized. For example, a file’s signature (also known as header or magic bytes) is the beginning bytes of a file and is often used to identify the file’s type. For example, the header of a JPEG file, is 0xFF 0xD8 and the file extension is either `.JPE`, `.JPEG` or `.JPG`.

T1055

Process Injection

T1497.003

Time Based Evasion

Adversaries may employ various time-based methods to detect and avoid virtualization and analysis environments. This may include enumerating time-based properties, such as uptime or the system clock, as well as the use of timers or other triggers to avoid a virtual machine environment (VME) or sandbox, specifically those that are automated or only operate for a limited amount of time.

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.

T1056.001

Keylogging

Adversaries may log user keystrokes to intercept credentials as the user types them. Keylogging is likely to be used to acquire credentials for new access opportunities when OS Credential Dumping efforts are not effective, and may require an adversary to intercept keystrokes on a system for a substantial period of time before credentials can be successfully captured. In order to increase the likelihood of capturing credentials quickly, an adversary may also perform actions such as clearing browser cookies to force users to reauthenticate to systems.

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.

TA0007

Discovery

The adversary is trying to figure out your environment. Discovery consists of techniques an adversary may use to gain knowledge about the system and internal network. These techniques help adversaries observe the environment and orient themselves before deciding how to act. They also allow adversaries to explore what they can control and what's around their entry point in order to discover how it could benefit their current objective. Native operating system tools are often used toward this post-compromise information-gathering objective.

T1010

Application Window Discovery

Adversaries may attempt to get a listing of open application windows. Window listings could convey information about how the system is used. For example, information about application windows could be used identify potential data to collect as well as identifying security tooling (Security Software Discovery) to evade.

T1083

File and Directory Discovery

Adversaries may enumerate files and directories or may search in specific locations of a host or network share for certain information within a file system. Adversaries may use the information from File and Directory Discovery during automated discovery to shape follow-on behaviors, including whether or not the adversary fully infects the target and/or attempts specific actions.

T1497.003

Time Based Evasion

TA0009

Collection

The adversary is trying to gather data of interest to their goal.

Collection consists of techniques adversaries may use to gather information and the sources information is collected from that are relevant to following through on the adversary's objectives. Frequently, the next goal after collecting data is to steal (exfiltrate) the data. Common target sources include various drive types, browsers, audio, video, and email. Common collection methods include capturing screenshots and keyboard input.

T1115

Clipboard Data

Adversaries may collect data stored in the clipboard from users copying information within or between applications.

For example, on Windows adversaries can access clipboard data by using clip.exe or Get-Clipboard.(Citation: MSDN Clipboard)(Citation: clip_win_server)(Citation: CISA_AA21_200B) Additionally, adversaries may monitor then replace users’ clipboard with their data (e.g., Transmitted Data Manipulation).(Citation: mining_ruby_reversinglabs)

macOS and Linux also have commands, such as pbpaste, to grab clipboard contents.(Citation: Operating with EmPyre)

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).