Backdoor.Win32.REMCOS.UGDL
Trojan:Win32/Execution!BV (Microsoft); Trojan-AitInject.aq (McAfee); Trojan.Win32.Crypt.ajhy (Kaspersky); Trojan.Win32.Generic!BT (Sunbelt)
Windows
![](/vinfo/imgFiles/legend.jpg)
Threat Type: Backdoor
Destructiveness: No
Encrypted:
In the wild: Yes
OVERVIEW
This Backdoor arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.
TECHNICAL DETAILS
Arrival Details
This Backdoor arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.
Installation
This Backdoor creates the following folders:
- %Application Data%\remcos
- %User Profile%\recdisc
(Note: %Application Data% is the current user's Application Data folder, which is usually C:\Documents and Settings\{user name}\Application Data on Windows 2000(32-bit), XP, and Server 2003(32-bit), or C:\Users\{user name}\AppData\Roaming on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit).. %User Profile% is the current user's profile folder, which is usually C:\Documents and Settings\{user name} on Windows 2000(32-bit), XP, and Server 2003(32-bit), or C:\Users\{user name} on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit).)
Autostart Technique
This Backdoor drops the following file(s) in the Windows User Startup folder to enable its automatic execution at every system startup:
- %User Startup%\recdisc.url
(Note: %User Startup% is the current user's Startup folder, which is usually C:\Windows\Profiles\{user name}\Start Menu\Programs\Startup on Windows 98 and ME, C:\WINNT\Profiles\{user name}\Start Menu\Programs\Startup on Windows NT, C:\Documents and Settings\{User name}\Start Menu\Programs\Startup on Windows 2003(32-bit), XP and 2000(32-bit), or C:\Users\{user name}\AppData\Roaming\Microsoft\Windows\Start Menu\Programs\Startup on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit), 10(64-bit).)
Other System Modifications
This Backdoor deletes the following files:
- %Application Data%\Mozilla\Firefox\Profiles\lj5mikyj.default\logins.json
- %Application Data%\Mozilla\Firefox\Profiles\lj5mikyj.default\cookies.sqlite
- %Application Data%\Mozilla\Firefox\Profiles\lj5mikyj.default\key3.db
(Note: %Application Data% is the current user's Application Data folder, which is usually C:\Documents and Settings\{user name}\Application Data on Windows 2000(32-bit), XP, and Server 2003(32-bit), or C:\Users\{user name}\AppData\Roaming on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit).)
It adds the following registry keys:
HKEY_CURRENT_USER\Software\Remcos-UFGYD9
It adds the following registry entries:
HKEY_CURRENT_USER\Software\Remcos-UFGYD9
exepath = "{random characters}"
HKEY_CURRENT_USER\Software\Remcos-UFGYD9
licence = "278F8A3F3CEAF86E793DC52B1083EB91"
HKEY_CURRENT_USER\Software\Remcos-UFGYD9
FR = "1"
Dropping Routine
This Backdoor drops the following files:
- %User Profile%\recdisc\recdisc.vbs
- %Application Data%\remcos\logs.dat
- %User Profile%\recdisc\proquota.exe
(Note: %User Profile% is the current user's profile folder, which is usually C:\Documents and Settings\{user name} on Windows 2000(32-bit), XP, and Server 2003(32-bit), or C:\Users\{user name} on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit).. %Application Data% is the current user's Application Data folder, which is usually C:\Documents and Settings\{user name}\Application Data on Windows 2000(32-bit), XP, and Server 2003(32-bit), or C:\Users\{user name}\AppData\Roaming on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit).)
Other Details
This Backdoor connects to the following possibly malicious URL:
- http://newlogs.{BLOCKED}o.org
This report is generated via an automated analysis system.
SOLUTION
Step 1
Before doing any scans, Windows 7, Windows 8, Windows 8.1, and Windows 10 users must disable System Restore to allow full scanning of their computers.
Step 2
Restart in Safe Mode
Step 3
Delete this registry key
Important: Editing the Windows Registry incorrectly can lead to irreversible system malfunction. Please do this step only if you know how or you can ask assistance from your system administrator. Else, check this Microsoft article first before modifying your computer's registry.
- In HKEY_CURRENT_USER\Software
- Remcos-UFGYD9
Step 4
Delete this registry value
Important: Editing the Windows Registry incorrectly can lead to irreversible system malfunction. Please do this step only if you know how or you can ask assistance from your system administrator. Else, check this Microsoft article first before modifying your computer's registry.
- In HKEY_CURRENT_USER\Software\Remcos-UFGYD9
- exepath = "{random characters}"
- In HKEY_CURRENT_USER\Software\Remcos-UFGYD9
- licence = "278F8A3F3CEAF86E793DC52B1083EB91"
- In HKEY_CURRENT_USER\Software\Remcos-UFGYD9
- FR = "1"
Step 5
Search and delete these components
- %User Profile%\recdisc\recdisc.vbs
- %Application Data%\remcos\logs.dat
- %User Profile%\recdisc\proquota.exe
Step 6
Search and delete these folders
- %Application Data%\remcos
- %User Profile%\recdisc
Step 7
Restart in normal mode and scan your computer with your Trend Micro product for files detected as Backdoor.Win32.REMCOS.UGDL. If the detected files have already been cleaned, deleted, or quarantined by your Trend Micro product, no further step is required. You may opt to simply delete the quarantined files. Please check this Knowledge Base page for more information.
Step 8
Restore this file from backup only Microsoft-related files will be restored. If this malware/grayware also deleted files related to programs that are not from Microsoft, please reinstall those programs on you computer again.
- %Application Data%\Mozilla\Firefox\Profiles\lj5mikyj.default\logins.json
- %Application Data%\Mozilla\Firefox\Profiles\lj5mikyj.default\cookies.sqlite
- %Application Data%\Mozilla\Firefox\Profiles\lj5mikyj.default\key3.db
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