Delphi based bot with DDoS capabilities (March 15, 2013)

Dell SonicWALL Threats Research team came across a Delphi based bot with DDoS capabilities along with support to execute multiple commands from the Command & Control (C&C) server. The author appears to refer this Malware as AyaBot.

Infection Cycle

Upon execution the Malware drops the following file on the system:

• %USERPROFILE%Local SettingsTempregdrv.exe (Copy of itself)

The Malware adds the following keys to the registry to enable startup after reboot:

• HKEY_CURRENT_USERSoftwareMicrosoftWindowsCurrentVersionRunRegistry Driver “%USERPROFILE%Local SettingsTempregdrv.exe”

It makes the following changes to the registry in order to bypass firewalls:

• HKEY_CURRENT_USERSoftwareMicrosoftWindowsCurrentVersionInternet SettingsZonemapProxyBypass=”1″
• HKEY_CURRENT_USERSoftwareMicrosoftWindowsCurrentVersionInternet SettingsZonemapIntranetName=”1″
• HKEY_CURRENT_USERSoftwareMicrosoftWindowsCurrentVersionInternet SettingsZonemapUNCAsIntranet=”1″

The following additions to the registry in HKEY_CURRENT_USERSoftwareRegDataData indicates the name AyaBot used by the creator:

During our analysis we observed AyaBot trying to access removable drives. AyaBot communicates with the server through Base64 encoded HTTP request and response, during our analysis we observed the following 3 phases of communication:

We observed a number of commands in the code, a few of them are listed below:

• update
• runexe
• config
• opensite
• openurl
• icmp
• pcdata

The AyaBot sample we received contains the following hardcoded URLs:

• etobylovjanvare.ru/0942c3aad278ce5ea571a61712b4506a.php
• pervogoaprela.ru/0942c3aad278ce5ea571a61712b4506a.php
• bylojarkonadvore.ru/0942c3aad278ce5ea571a61712b4506a.php
• nogiledeneli.ru/0942c3aad278ce5ea571a61712b4506a.php
• areyouaredo.com/0942c3aad278ce5ea571a61712b4506a.php

During our analysis we observed AyaBot successfully communicating with the following URL:

• reklamamarketing.ru/content/blocks/classes/s.php

areyouaredo.com is one of the sites the bot tries to communicate with. This site provides DDoS attack services for a nominal fee as shown by their price chart below.

Similarities in the name of this site and the bot (AreYouAredo.com) suggests that this bot may be part of the site’s DDoS network, once a victim machine is infected it may play a role in a targeted DDoS attack as part of their services.

Dell SonicWALL Gateway AntiVirus provides protection against this threat via the following signature:

• GAV: Delf.OEJ_2 (Trojan)

Security News

The SonicWall Capture Labs Threat Research Team gathers, analyzes and vets cross-vector threat information from the SonicWall Capture Threat network, consisting of global devices and resources, including more than 1 million security sensors in nearly 200 countries and territories. The research team identifies, analyzes, and mitigates critical vulnerabilities and malware daily through in-depth research, which drives protection for all SonicWall customers. In addition to safeguarding networks globally, the research team supports the larger threat intelligence community by releasing weekly deep technical analyses of the most critical threats to small businesses, providing critical knowledge that defenders need to protect their networks.