BKDR_TELEBOT.VBS
Windows 64 bit
Threat Type: Backdoor
Destructiveness: No
Encrypted: No
In the wild: Yes
OVERVIEW
Dropped by other malware, Downloaded from the Internet
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.
It executes commands from a remote malicious user, effectively compromising the affected system. It connects to a website to send and receive information.
It gathers information and reports it to its servers.
TECHNICAL DETAILS
310,784 bytes
EXE
No
04 Jan 2017
Drops files, Connects to URLs/IPs, Steals information
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 drops and executes the following files:
- %User Temp%\~DF{random}.bat ← used to update/delete itself; deleted afterwards
(Note: %User Temp% is the user's temporary folder, where it usually is C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\AppData\Local\Temp on Windows Vista (32- and 64-bit), Windows 7 (32- and 64-bit), Windows 8 (32- and 64-bit), Windows 8.1 (32- and 64-bit), Windows Server 2008, and Windows Server 2012.)
Autostart Technique
This backdoor registers itself as a system service to ensure its automatic execution at every system startup by adding the following registry entries:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
services\Windows Defender (if running as Admin)
Start = "2"
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
services\Windows Defender (if running as Admin)
ErrorControl = "0"
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
services\Windows Defender (if running as Admin)
ImagePath = "%System%\cmd.exe /c {malware path and filename}"
It adds the following registry entries to enable its automatic execution at every system startup:
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run (if not running as Admin)
csrss.exe = "{malware path and filename}"
It registers as a system service to ensure its automatic execution at every system startup by adding the following registry keys:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
services\Windows Defender (if running as Admin)
Backdoor Routine
This backdoor executes the following commands from a remote malicious user:
- kernel32.dll - Execute shell command w/o feedback
- ws2_32.dll - Execute file remotely across network
- wscapi.dll - Execute shell command w/ feedback
- wsock32.dll - Decode date and save to file
- CertEnroll.dll - Update self
- ddraw.dll - Get malware version
- esent.dll - Set sleep time
- imapi2.dll - Terminate itself
- mscoree.dll - Delete and terminate itself
- netapi32.dll - Upload file
It connects to the following websites to send and receive information:
- https://{BLOCKED}.{BLOCKED}.37.3/services/nl-nl/power-bi-embedded/wt_mc_id/azuremktg_hp_powerbiembedded
- https://{BLOCKED}.{BLOCKED}.37.3/store/mseea/nl_NL/cat/Accessoires/categoryID_66233400?p={params}
- where {params} is encoded string of the following data:
- m={mac_address}&n={hostname}&t={sleeptime}&r={random}
As of this writing, the said servers are currently inaccessible.
Stolen Information
This backdoor sends the gathered information via HTTP POST to the following URL:
- https://{BLOCKED}.{BLOCKED}.37.3/store/mseea/nl_NL/cat/Back-to-School/categoryID_68073200
Other Details
This backdoor drops the following file(s)/component(s):
- %User Temp%\~DF{random}.tmp ← downloaded files; log files; deleted afterwards
(Note: %User Temp% is the user's temporary folder, where it usually is C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\AppData\Local\Temp on Windows Vista (32- and 64-bit), Windows 7 (32- and 64-bit), Windows 8 (32- and 64-bit), Windows 8.1 (32- and 64-bit), Windows Server 2008, and Windows Server 2012.)
It gathers the following information and reports it to its servers:
- Host Name
- MAC Address
SOLUTION
9.800
13.146.07
09 Jan 2017
13.147.00
10 Jan 2017
Step 1
Before doing any scans, Windows XP, Windows Vista, and Windows 7 users must disable System Restore to allow full scanning of their computers.
Step 2
Note that not all files, folders, and registry keys and entries are installed on your computer during this malware's/spyware's/grayware's execution. This may be due to incomplete installation or other operating system conditions. If you do not find the same files/folders/registry information, please proceed to the next step.
Step 3
Restart in Safe Mode
Step 4
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_LOCAL_MACHINE\SYSTEM\CurrentControlSet\services
- Windows Defender
- Windows Defender
Step 5
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\Microsoft\Windows\CurrentVersion\Run
- csrss.exe = "{malware path and filename}"
- csrss.exe = "{malware path and filename}"
Step 6
Search and delete this file
- %User Temp%\~DF{random}.tmp
- %User Temp%\~DF{random}.bat
Step 7
Restart in normal mode and scan your computer with your Trend Micro product for files detected as BKDR_TELEBOT.VBS. 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.
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