Trojan.Win32.Bumat_5c1ab7a5b9

Dynamic Analysis

Payload

No specific payload has been found.

Process activity

The Trojan creates the following process(es):

sc.exe:1700
sc.exe:1052
sc.exe:952
sc.exe:940
sc.exe:444
sc.exe:828
net1.exe:1868
net1.exe:1072
net.exe:1784
net.exe:816
%original file name%.exe:512
mshta.exe:1292

The Trojan injects its code into the following process(es):

gohrbg.exe:1160

File activity

The process %original file name%.exe:512 makes changes in the file system.

The Trojan creates and/or writes to the following file(s):

%Documents and Settings%\%current user%\Application Data\Microsoft\gohrbg.exe (1762816 bytes)
%Documents and Settings%\%current user%\Application Data\Microsoft (4096 bytes)

The process mshta.exe:1292 makes changes in the file system.

The Trojan creates and/or writes to the following file(s):

%Documents and Settings%\%current user%\Local Settings\Temporary Internet Files\Content.IE5\desktop.ini (67 bytes)

Registry activity

The process sc.exe:1700 makes changes in the system registry.

The Trojan creates and/or sets the following values in system registry:

[HKLM\SOFTWARE\Microsoft\Cryptography\RNG]
"Seed" = "C3 BD DB C7 A4 56 70 A7 0D FE 8C 3B 27 3D 5B 67"

The process sc.exe:1052 makes changes in the system registry.

The Trojan creates and/or sets the following values in system registry:

[HKLM\SOFTWARE\Microsoft\Cryptography\RNG]
"Seed" = "BB 33 0F 17 F1 D6 14 63 86 54 15 E5 18 32 A6 DC"

The process sc.exe:952 makes changes in the system registry.

The Trojan creates and/or sets the following values in system registry:

[HKLM\SOFTWARE\Microsoft\Cryptography\RNG]
"Seed" = "D7 CB 63 FD F1 80 85 4D 19 37 94 67 C6 DA 97 36"

The process sc.exe:940 makes changes in the system registry.

The Trojan creates and/or sets the following values in system registry:

[HKLM\SOFTWARE\Microsoft\Cryptography\RNG]
"Seed" = "04 86 62 B4 08 6A CE 0F 47 5F E1 87 5A C8 9C 3D"

The process sc.exe:444 makes changes in the system registry.

The Trojan creates and/or sets the following values in system registry:

[HKLM\SOFTWARE\Microsoft\Cryptography\RNG]
"Seed" = "0E 71 08 7D F1 38 87 0B D8 CE 92 AE 37 36 E7 47"

The process sc.exe:828 makes changes in the system registry.

The Trojan creates and/or sets the following values in system registry:

[HKLM\SOFTWARE\Microsoft\Cryptography\RNG]
"Seed" = "E3 D8 5E 29 52 85 BC 9B 79 1A A9 CA 48 4E E0 33"

The process net1.exe:1868 makes changes in the system registry.

The Trojan creates and/or sets the following values in system registry:

[HKLM\SOFTWARE\Microsoft\Cryptography\RNG]
"Seed" = "0D 42 7E 99 9E 06 0E DF 92 D7 B2 D3 68 5E B7 5A"

The process net1.exe:1072 makes changes in the system registry.

The Trojan creates and/or sets the following values in system registry:

[HKLM\SOFTWARE\Microsoft\Cryptography\RNG]
"Seed" = "AD F0 70 17 18 53 00 7A CE D6 E1 B1 2C C6 85 67"

The process net.exe:1784 makes changes in the system registry.

The Trojan creates and/or sets the following values in system registry:

[HKLM\SOFTWARE\Microsoft\Cryptography\RNG]
"Seed" = "DA CB F8 2D 07 BF 4B 3B B1 9D 8F BA DA 9B A6 FF"

The process net.exe:816 makes changes in the system registry.

The Trojan creates and/or sets the following values in system registry:

[HKLM\SOFTWARE\Microsoft\Cryptography\RNG]
"Seed" = "41 F7 27 27 58 91 6B 35 8E B2 2D 67 4F FC E9 85"

The process gohrbg.exe:1160 makes changes in the system registry.

The Trojan creates and/or sets the following values in system registry:

[HKLM\SOFTWARE\Microsoft\Cryptography\RNG]
"Seed" = "0F 74 46 7E 1F D9 8A 1C 8B C1 6A 6B 82 74 49 BD"

[HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Image File Execution Options\MSASCui.exe]
"debugger" = "svchost.exe"

[HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Image File Execution Options\msseces.exe]
"debugger" = "svchost.exe"

[HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Image File Execution Options\ekrn.exe]
"debugger" = "svchost.exe"

[HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Internet Settings]
"WarnOnHTTPSToHTTPRedirect" = "0"

[HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Image File Execution Options\avastSvc.exe]
"debugger" = "svchost.exe"

[HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Image File Execution Options\egui.exe]
"debugger" = "svchost.exe"

[HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer\Shell Folders]
"AppData" = "%Documents and Settings%\%current user%\Application Data"

[HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Image File Execution Options\msmpeng.exe]
"debugger" = "svchost.exe"

[HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Image File Execution Options\afwserv.exe]
"debugger" = "svchost.exe"

[HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer]
"SysCert" = "DD 07 09 00 01 00 1E 00 0F 00 1B 00 03 00 D9 00"

[HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Image File Execution Options\avastUI.exe]
"debugger" = "svchost.exe"

[HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion\SystemRestore]
"DisableSR " = "1"

[HKCU\Software\Microsoft\Windows\CurrentVersion\Internet Settings]
"WarnOnHTTPSToHTTPRedirect" = "0"

The Trojan adds the reference to itself to be executed when a user logs on:

[HKCU\Software\Microsoft\Windows NT\CurrentVersion\Winlogon]
"Shell" = "%Documents and Settings%\%current user%\Application Data\Microsoft\gohrbg.exe"

The process %original file name%.exe:512 makes changes in the system registry.

The Trojan creates and/or sets the following values in system registry:

[HKLM\SOFTWARE\Microsoft\Cryptography\RNG]
"Seed" = "5F 63 AD D5 9D 85 ED E2 C6 E1 6F 1F CC 44 F8 A5"

[HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer\Shell Folders]
"Cookies" = "%Documents and Settings%\%current user%\Cookies"

[HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\Shell Folders]
"Common Documents" = "%Documents and Settings%\All Users\Документы"

[HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer\Shell Folders]
"Desktop" = "%Documents and Settings%\%current user%\Рабочий стол"

[HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer\MountPoints2\{ebcf8d94-66db-11de-b228-806d6172696f}]
"BaseClass" = "Drive"

[HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer\Shell Folders]
"Cache" = "%Documents and Settings%\%current user%\Local Settings\Temporary Internet Files"

[HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer\MountPoints2\{d8c0d8da-77bd-11e0-bb02-000c293bc0fd}]
"BaseClass" = "Drive"

[HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer\Shell Folders]
"AppData" = "%Documents and Settings%\%current user%\Application Data"

[HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer\MountPoints2\{91167d42-103d-11db-8c91-806d6172696f}]
"BaseClass" = "Drive"

[HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\Shell Folders]
"Common Desktop" = "%Documents and Settings%\All Users\Рабочий стол"

[HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer\Shell Folders]
"Personal" = "%Documents and Settings%\%current user%\Мои документы"

[HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer\MountPoints2\{91167d45-103d-11db-8c91-806d6172696f}]
"BaseClass" = "Drive"

The Trojan modifies IE settings for security zones to map all urls to the Intranet Zone:

[HKCU\Software\Microsoft\Windows\CurrentVersion\Internet Settings\ZoneMap]
"IntranetName" = "1"

The Trojan modifies IE settings for security zones to map all local web-nodes with no dots which do not refer to any zone to the Intranet Zone:

"UNCAsIntranet" = "1"

The Trojan modifies IE settings for security zones to map all web-nodes that bypassing the proxy to the Intranet Zone:

"ProxyBypass" = "1"

The process mshta.exe:1292 makes changes in the system registry.

The Trojan creates and/or sets the following values in system registry:

[HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Internet Settings\Cache\Paths]
"Directory" = "%Documents and Settings%\%current user%\Local Settings\Temporary Internet Files\Content.IE5"

[HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Internet Settings\Cache\Paths\path4]
"CacheLimit" = "65324"
"CachePath" = "%Documents and Settings%\%current user%\Local Settings\Temporary Internet Files\Content.IE5\Cache4"

[HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Internet Settings\Cache\Paths\path2]
"CacheLimit" = "65324"

[HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer\Shell Folders]
"AppData" = "%Documents and Settings%\%current user%\Application Data"

"Cookies" = "%Documents and Settings%\%current user%\Cookies"

[HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Internet Settings\Cache\Paths\path2]
"CachePath" = "%Documents and Settings%\%current user%\Local Settings\Temporary Internet Files\Content.IE5\Cache2"

[HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\Shell Folders]
"Common AppData" = "%Documents and Settings%\All Users\Application Data"

[HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer\Shell Folders]
"Cache" = "%Documents and Settings%\%current user%\Local Settings\Temporary Internet Files"

[HKLM\System\CurrentControlSet\Hardware Profiles\0001\Software\Microsoft\windows\CurrentVersion\Internet Settings]
"ProxyEnable" = "0"

[HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Internet Settings\Cache\Paths\path1]
"CacheLimit" = "65324"

[HKCU\Software\Microsoft\Windows\CurrentVersion\Internet Settings\Connections]
"SavedLegacySettings" = "3C 00 00 00 0C 00 00 00 01 00 00 00 00 00 00 00"

[HKLM\SOFTWARE\Microsoft\Cryptography\RNG]
"Seed" = "0E E8 FA 6B 54 AD 5A BE B2 91 19 D7 84 08 3E 58"

[HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Internet Settings\Cache\Paths\path1]
"CachePath" = "%Documents and Settings%\%current user%\Local Settings\Temporary Internet Files\Content.IE5\Cache1"

[HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Internet Settings\Cache\Paths\path3]
"CacheLimit" = "65324"

[HKCU\Software\Microsoft\Windows\CurrentVersion\Internet Settings]
"MigrateProxy" = "1"

[HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer\Shell Folders]
"History" = "%Documents and Settings%\%current user%\Local Settings\History"

[HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Internet Settings\Cache\Paths\path3]
"CachePath" = "%Documents and Settings%\%current user%\Local Settings\Temporary Internet Files\Content.IE5\Cache3"

[HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Internet Settings\Cache\Paths]
"Paths" = "4"

The Trojan modifies IE settings for security zones to map all local web-nodes with no dots which do not refer to any zone to the Intranet Zone:

[HKCU\Software\Microsoft\Windows\CurrentVersion\Internet Settings\ZoneMap]
"UNCAsIntranet" = "1"

The Trojan modifies IE settings for security zones to map all web-nodes that bypassing the proxy to the Intranet Zone:

"ProxyBypass" = "1"

Proxy settings are disabled:

[HKCU\Software\Microsoft\Windows\CurrentVersion\Internet Settings]
"ProxyEnable" = "0"

The Trojan modifies IE settings for security zones to map all urls to the Intranet Zone:

[HKCU\Software\Microsoft\Windows\CurrentVersion\Internet Settings\ZoneMap]
"IntranetName" = "1"

The Trojan deletes the following value(s) in system registry:

[HKCU\Software\Microsoft\Windows\CurrentVersion\Internet Settings]
"AutoConfigURL"
"ProxyServer"
"ProxyOverride"

Network activity (URLs)

URL	IP
pcguard-online.com	Unresolvable

HOSTS file anomalies

No changes have been detected.

Rootkit activity

No anomalies have been detected.

Propagation

Removals

Remove it with Ad-Aware

1. Click (here) to download and install Ad-Aware Free Antivirus.
2. Update the definition files.
3. Run a full scan of your computer.

Manual removal*

1. Terminate malicious process(es) (How to End a Process With the Task Manager):

   sc.exe:1700
   sc.exe:1052
   sc.exe:952
   sc.exe:940
   sc.exe:444
   sc.exe:828
   net1.exe:1868
   net1.exe:1072
   net.exe:1784
   net.exe:816
   %original file name%.exe:512
   mshta.exe:1292

2. Delete the original Trojan file.
   
3. Delete or disinfect the following files created/modified by the Trojan:

   %Documents and Settings%\%current user%\Application Data\Microsoft\gohrbg.exe (1762816 bytes)
   %Documents and Settings%\%current user%\Local Settings\Temporary Internet Files\Content.IE5\desktop.ini (67 bytes)

4. Remove the references to the Trojan by modifying the following registry value(s) (How to Work with System Registry):

   [HKCU\Software\Microsoft\Windows NT\CurrentVersion\Winlogon]
   "Shell" = "%Documents and Settings%\%current user%\Application Data\Microsoft\gohrbg.exe"

5. Clean the Temporary Internet Files folder, which may contain infected files (How to clean Temporary Internet Files folder).
   
6. Reboot the computer.
   

*Manual removal may cause unexpected system behaviour and should be performed at your own risk.

Static Analysis

Network Activity

Map

Strings from Dumps