TROJ_SISRON.YNF
Windows 2000, Windows XP, Windows Server 2003
Threat Type: Trojan
Destructiveness: No
Encrypted:
In the wild: Yes
OVERVIEW
This Trojan arrives as an attachment to email messages spammed by other malware/grayware or malicious users. It arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.
It attempts to steal information, such as user names and passwords, used when logging into certain banking or finance-related websites.
TECHNICAL DETAILS
209,408 bytes
EXE
Yes
21 Feb 2014
Arrival Details
This Trojan arrives as an attachment to email messages spammed by other malware/grayware or malicious users.
It 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 Trojan drops the following copies of itself into the affected system:
- %System%\{random value}.exe
(Note: %System% is the Windows system folder, which is usually C:\Windows\System32.)
Autostart Technique
This Trojan adds the following registry entries to enable its automatic execution at every system startup:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
{random value} = "%System%\{random value}.exe"
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
{random value} = "%System%\{random value}.exe"
Information Theft
This Trojan attempts to steal information from the following banks and/or other financial institutions:
- Casas Bahia
- Banco Bradesco
- HSBC Internet
- Braspag Payment Technology
- Sicredi
Stolen Information
The stolen information is saved in the following file:
- %User Temp%\{random value}
(Note: %User Temp% is the current user's Temp folder, which is usually C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000, XP, and Server 2003, or C:\Users\{user name}\AppData\Local\Temp on Windows Vista and 7.)
It sends the data it gathers to the following email addresses via SMTP:
- {BLOCKED}2015@{BLOCKED}ol.com.br
- {BLOCKED}il2013@{BLOCKED}il.com
- {BLOCKED}mar-brito@{BLOCKED}ol.com.br
- {BLOCKED}il2014@{BLOCKED}il.com
Drop Points
This Trojan uses its own SMTP engine to send the stolen data using the following domain server:
- {BLOCKED}s.{BLOCKED}l.com.br
- {BLOCKED}es.{BLOCKED}l.com.br
- {BLOCKED}ot.{BLOCKED}l.com.br
- {BLOCKED}s.{BLOCKED}ol.com.br
- {BLOCKED}ps.{BLOCKED}ol.com.br
SOLUTION
9.300
10.614.05
26 Jan 2014
10.615.00
27 Jan 2014
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
Scan your computer with your Trend Micro product and note files detected as TROJ_SISRON.YNF
Step 3
Restart in Safe Mode
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_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
- {random value} = "%System%\{random value}.exe"
- {random value} = "%System%\{random value}.exe"
- In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run
- {random value} = "%System%\{random value}.exe"
- {random value} = "%System%\{random value}.exe"
Step 5
Search and delete these components
- %User Temp%\{random value}
Step 6
Restart in normal mode and scan your computer with your Trend Micro product for files detected as TROJ_SISRON.YNF. 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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