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TrojanSpy:Win32/Bancos.TA


TrojanSpy:Win32/Bancos.TA is a data-stealing trojan that captures online banking credentials, such as account login names and passwords, then relays the captured information to a remote attacker. Win32/Bancos.TA targets customers of the Brazilian bank "Banco Bradesco".


What to do now

Manual removal is not recommended for this threat. To detect and remove this threat and other malicious software that may have been installed, run a full-system scan with an up-to-date antivirus product such as Microsoft Security Essentials, or the Microsoft Safety Scanner. For more information about using antivirus software, see http://www.microsoft.com/security/antivirus/av.aspx.

Threat behavior

TrojanSpy:Win32/Bancos.TA is a data-stealing trojan that captures online banking credentials, such as account login names and passwords, then relays the captured information to a remote attacker. Win32/Bancos.TA targets customers of the Brazilian bank "Banco Bradesco".
Installation
When run, TrojanSpy:Win32/Bancos.TA  creates copies of itself as "%Appdata%\spoolsv.exe" and "%Temp%\services". It ensures that its copy automatically runs every time Windows starts by creating the following registry entry:
 
Adds value: "MicrosoftWinUpdate"
With data: "%Appdata%\spoolsv.exe"
To subkey: HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
Payload
Steals user data
TrojanSpy:Win32/Bancos.TA monitors the computer to see if the user visits the following Web site:
 
  • bradesco.com.br
 
This is the online banking Web site for the bank "Banco Bradesco". If this site is visited, TrojanSpy:Win32/Bancos.TA modifies the contents of the Web page as it is loaded by injecting code that can capture sensitive user details, such as user names and passwords for the site.
 
The captured details are sent to a remote attacker at "avsnew.zxq.net" using HTTP POST.
 
Downloads arbitrary files
TrojanSpy:Win32/Bancos.TA can download arbitrary files from the Web site "greatisweb.com". These files may be detected as other malware.
 
Analysis by Marian Radu

Symptoms

System changes
The following system changes may indicate the presence of this malware:
  • The presence of the following file:
    %Appdata%\spoolsv.exe
  • The presence of the following registry modifications:
    Added value: "MicrosoftWinUpdate"
    With data: "%Appdata%\spoolsv.exe"
    To subkey: HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Run

Prevention


Alert level: Severe
First detected by definition: 1.77.388.0
Latest detected by definition: 1.173.2373.0 and higher
First detected on: Mar 05, 2010
This entry was first published on: Mar 04, 2010
This entry was updated on: Apr 17, 2011

This threat is also detected as:
  • Trojan.Win32.Cosmu.fgi (Kaspersky)
  • PSW.Banker5.ALNN (AVG)
  • TR/Cosmu.fgi (Avira)
  • DeepScan:Generic.Banker.Delf.E238106B (BitDefender)
  • Trojan.PWS.Banker.origin (Dr.Web)
  • Win32/Spy.Banbra.NTN (ESET)
  • PWS-Banker!eao (McAfee)
  • TROJ_COSMU.CM (Trend Micro)