Kaspersky Threats — Worm.Win32.Vobfus.xn

クラス: Worm

ワームは、ネットワークリソースを介してコンピュータネットワーク上に広まります。 Net-Wormとは異なり、ユーザーはワームを起動して起動する必要があります。この種のワームは、リモートのコンピュータネットワークを検索し、読み書き可能なディレクトリに自身をコピーします（見つかった場合）。さらに、これらのワームは、内蔵のオペレーティングシステム機能を使用して、アクセス可能なネットワークディレクトリを検索したり、インターネット上のコンピュータをランダムに検索したり、それらに接続したり、これらのコンピュータのディスクに完全にアクセスしようとします。また、このカテゴリには、1つまたは複数の理由で、上記で定義した他のカテゴリ（モバイルデバイス用のワームなど）に適合しないワームも含まれます。

プラットフォーム: Win32

Win32は、32ビットアプリケーションの実行をサポートするWindows NTベースのオペレーティングシステム（Windows XP、Windows 7など）上のAPIです。世界で最も広く普及しているプログラミングプラットフォームの1つです。

ファミリー: Worm.Win32.Vobfus

No family description

Examples

C5B094BD32591843E4A60BFD66C200B8
7C46E5C2745320BC497D68847D49A070
AED03A8C6C6AED54440B1EDEC6357869
E9140E1E1F076F0E859D6483FA743E77
271F0427F2634B75EC9D5A775EAE612C

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.

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.

T1564.001

Hidden Files and Directories

Adversaries may set files and directories to be hidden to evade detection mechanisms. To prevent normal users from accidentally changing special files on a system, most operating systems have the concept of a ‘hidden’ file. These files don’t show up when a user browses the file system with a GUI or when using normal commands on the command line. Users must explicitly ask to show the hidden files either via a series of Graphical User Interface (GUI) prompts or with command line switches (dir /a for Windows and ls –a for Linux and macOS).

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.

T1572

Protocol Tunneling

Adversaries may tunnel network communications to and from a victim system within a separate protocol to avoid detection/network filtering and/or enable access to otherwise unreachable systems. Tunneling involves explicitly encapsulating a protocol within another. This behavior may conceal malicious traffic by blending in with existing traffic and/or provide an outer layer of encryption (similar to a VPN). Tunneling could also enable routing of network packets that would otherwise not reach their intended destination, such as SMB, RDP, or other traffic that would be filtered by network appliances or not routed over the Internet.

There are various means to encapsulate a protocol within another protocol. For example, adversaries may perform SSH tunneling (also known as SSH port forwarding), which involves forwarding arbitrary data over an encrypted SSH tunnel.(Citation: SSH Tunneling)

Protocol Tunneling may also be abused by adversaries during Dynamic Resolution. Known as DNS over HTTPS (DoH), queries to resolve C2 infrastructure may be encapsulated within encrypted HTTPS packets.(Citation: BleepingComp Godlua JUL19)

Adversaries may also leverage Protocol Tunneling in conjunction with Proxy and/or Protocol Impersonation to further conceal C2 communications and infrastructure.