Kaspersky Threats — Backdoor.Win32.Lotok.ssn

クラス: Backdoor

バックドアは、悪意のあるユーザーが感染したコンピュータをリモートコントロールできるように設計されています。機能性の面では、バックドアはソフトウェア開発者が設計し配布する多くの管理システムに似ています。これらの種類の悪質なプログラムは、ファイルの送受信、ファイルの起動や削除、メッセージの表示、データの削除、コンピュータの再起動など、感染したコンピュータ上で必要な作業を可能にします。このカテゴリのプログラムは、被害者のコンピュータのグループを結びつけ、ボットネットまたはゾンビネットワークを形成するためです。これにより、悪意のあるユーザーは感染したコンピュータの軍隊を集中管理し、犯罪目的で使用することができます。 Net-Wormのように、ネットワークを介して拡散して他のコンピュータに感染することができるバックドアのグループもあります。違いは、このようなBackdoorは（Net-Wormのように）自動的に広がるのではなく、それらを制御する悪意のあるユーザーからの特別な「コマンド」に限られるということです。

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: Backdoor.Win32.Lotok

No family description

Examples

00FD3FC7DB0079A16DC5BCDF6D1A2FCB
07F4B43C488F02925C2E1DDFC43129B0
657161CBD1CD44FCCE54580D261EF857
D44F2F1A94FDB5C419B51AC7AE86C3B7
9FB99FF4278BFFE0CA8A743AA0BB40A6

Tactics and Techniques: Mitre*

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

Masquerading

Adversaries may attempt to manipulate features of their artifacts to make them appear legitimate or benign to users and/or security tools. Masquerading occurs when the name or location of an object, legitimate or malicious, is manipulated or abused for the sake of evading defenses and observation. This may include manipulating file metadata, tricking users into misidentifying the file type, and giving legitimate task or service names.

Renaming abusable system utilities to evade security monitoring is also a form of Masquerading.(Citation: LOLBAS Main Site) Masquerading may also include the use of Proxy or VPNs to disguise IP addresses, which can allow adversaries to blend in with normal network traffic and bypass conditional access policies or anti-abuse protections.

T1055.012

Process Injection: Process Hollowing

Adversaries may inject malicious code into suspended and hollowed processes in order to evade process-based defenses. Process hollowing is a method of executing arbitrary code in the address space of a separate live process.

Process hollowing is commonly performed by creating a process in a suspended state then unmapping/hollowing its memory, which can then be replaced with malicious code. A victim process can be created with native Windows API calls such as CreateProcess, which includes a flag to suspend the processes primary thread. At this point the process can be unmapped using APIs calls such as ZwUnmapViewOfSection or NtUnmapViewOfSection before being written to, realigned to the injected code, and resumed via VirtualAllocEx, WriteProcessMemory, SetThreadContext, then ResumeThread respectively.(Citation: Leitch Hollowing)(Citation: Elastic Process Injection July 2017)

This is very similar to Thread Local Storage but creates a new process rather than targeting an existing process. This behavior will likely not result in elevated privileges since the injected process was spawned from (and thus inherits the security context) of the injecting process. However, execution via process hollowing may also evade detection from security products since the execution is masked under a legitimate process.