Backdoor.Win32.PcClient_63ed7ac86f

Dynamic Analysis

Payload

No specific payload has been found.

Process activity

The Backdoor creates the following process(es):

58685.exe:1712
img_snapshot.exe:1088
%original file name%.exe:600

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

58685.exe:1128
rundll32.exe:1252

File activity

The process 58685.exe:1128 makes changes in the file system.

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

%Documents and Settings%\%current user%\Application Data\srvhosts1\srv.exe.exe (1038342 bytes)
%Documents and Settings%\%current user%\Application Data\r58Ies.tmp (18 bytes)
%System%\wbem\Logs\wbemprox.log (76 bytes)
%Documents and Settings%\%current user%\Главное меню\Программы\Автозагрузка\srv.exe.exe (519171 bytes)
%Documents and Settings%\%current user%\Application Data\test.txt (64 bytes)

The Backdoor deletes the following file(s):

%Documents and Settings%\%current user%\Application Data\srvhosts1\srv.exe.exe (0 bytes)
%Documents and Settings%\%current user%\Application Data\srvhosts1 (0 bytes)

The process 58685.exe:1712 makes changes in the file system.

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

%Documents and Settings%\%current user%\Application Data\58685\58685.exe (519171 bytes)

The process img_snapshot.exe:1088 makes changes in the file system.

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

%Documents and Settings%\%current user%\Local Settings\Temp\58685.exe (781315 bytes)

The process %original file name%.exe:600 makes changes in the file system.

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

%Documents and Settings%\%current user%\Local Settings\Application Data\GDIPFONTCACHEV1.DAT (18432 bytes)
%Documents and Settings%\%current user%\Local Settings\Temp\img_snapshot.exe (1263104 bytes)
%Documents and Settings%\%current user%\Local Settings\Temp\uyrfg.png (143594 bytes)

Registry activity

The process 58685.exe:1128 makes changes in the system registry.

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

[HKLM\SOFTWARE\Microsoft\Cryptography\RNG]
"Seed" = "F1 C5 F7 D2 FB 45 42 3F 61 21 8F 89 07 8D 2D B1"

[HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer\Shell Folders]
"Startup" = "%Documents and Settings%\%current user%\Главное меню\Программы\Автозагрузка"
"Local AppData" = "%Documents and Settings%\%current user%\Local Settings\Application Data"
"AppData" = "%Documents and Settings%\%current user%\Application Data"
"Cache" = "%Documents and Settings%\%current user%\Local Settings\Temporary Internet Files"

[HKCU\Environment]
"SEE_MASK_NOZONECHECKS" = "1"

To automatically run itself each time Windows is booted, the Backdoor adds the following link to its file to the system registry autorun key:

[HKCU\Software\Microsoft\Windows\CurrentVersion\Run]
"srvhosts" = "%Documents and Settings%\%current user%\Application Data\srvhosts1\srv.exe.exe"

The process 58685.exe:1712 makes changes in the system registry.

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

[HKLM\SOFTWARE\Microsoft\Cryptography\RNG]
"Seed" = "61 32 64 7B 88 C6 1E 85 00 9F 87 69 4F B3 5A 6A"

[HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer\Shell Folders]
"Cookies" = "%Documents and Settings%\%current user%\Cookies"
"Startup" = "%Documents and Settings%\%current user%\Главное меню\Программы\Автозагрузка"
"Local AppData" = "%Documents and Settings%\%current user%\Local Settings\Application Data"
"Desktop" = "%Documents and Settings%\%current user%\Рабочий стол"

[HKCU\Software\Microsoft\Windows\ShellNoRoam\MUICache\%Documents and Settings%\%current user%\Application Data\58685]
"58685.exe" = "Windows Sidebar"

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

[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]
"Cache" = "%Documents and Settings%\%current user%\Local Settings\Temporary Internet Files"

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

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

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

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

"ProxyBypass" = "1"

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

"IntranetName" = "1"

The process img_snapshot.exe:1088 makes changes in the system registry.

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

[HKLM\SOFTWARE\Microsoft\Cryptography\RNG]
"Seed" = "29 BE 64 38 06 8A B8 AD 26 AA 6C 10 8A 89 6E 55"

[HKCU\Software\Microsoft\Windows\ShellNoRoam\MUICache\%Documents and Settings%\%current user%\Local Settings\Temp]
"58685.exe" = "Windows Sidebar"

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

[HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer\MountPoints2\{91167d45-103d-11db-8c91-806d6172696f}]
"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\MountPoints2\{91167d42-103d-11db-8c91-806d6172696f}]
"BaseClass" = "Drive"

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

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

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

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

"IntranetName" = "1"

The Backdoor 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 process %original file name%.exe:600 makes changes in the system registry.

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

[HKLM\SOFTWARE\Microsoft\Cryptography\RNG]
"Seed" = "48 86 FC C2 0A 4B E3 94 84 A3 37 AC EF 72 48 9C"

[HKCU\Software\Microsoft\Windows\ShellNoRoam\MUICache\%Documents and Settings%\%current user%\Local Settings\Temp]
"img_snapshot.exe" = "Windows Sidebar"

[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\ShellNoRoam\MUICache\%System%]
"shimgvw.dll" = "Программа просмотра изображений и факсов"

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

[HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer\MountPoints2\{91167d45-103d-11db-8c91-806d6172696f}]
"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\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\{ebcf8d94-66db-11de-b228-806d6172696f}]
"BaseClass" = "Drive"

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

"ProxyBypass" = "1"

The process rundll32.exe:1252 makes changes in the system registry.

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

[HKLM\SOFTWARE\Microsoft\Cryptography\RNG]
"Seed" = "5F 6C 1E 7E AB E1 A1 80 14 31 05 51 A9 61 83 2C"

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

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

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

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

Dropped PE files

MD5	File path
b214054a3814d5522e6e043aa99fe947	c:\Documents and Settings\test\Application Data\58685\58685.exe
b214054a3814d5522e6e043aa99fe947	c:\Documents and Settings\test\Application Data\srvhosts1\srv.exe.exe
b214054a3814d5522e6e043aa99fe947	c:\Documents and Settings\test\Local Settings\Temp\58685.exe
1961563261f3d2941c3f042435152adf	c:\Documents and Settings\test\Local Settings\Temp\img_snapshot.exe
b214054a3814d5522e6e043aa99fe947	c:\Documents and Settings\test\Ãëàâíîå ìåíþ\Ïðîãðàììû\Àâòîçàãðóçêà\srv.exe.exe

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):

   58685.exe:1712
   img_snapshot.exe:1088
   %original file name%.exe:600
   

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

   %Documents and Settings%\%current user%\Application Data\srvhosts1\srv.exe.exe (1038342 bytes)
   %Documents and Settings%\%current user%\Application Data\r58Ies.tmp (18 bytes)
   %System%\wbem\Logs\wbemprox.log (76 bytes)
   %Documents and Settings%\%current user%\Главное меню\Программы\Автозагрузка\srv.exe.exe (519171 bytes)
   %Documents and Settings%\%current user%\Application Data\test.txt (64 bytes)
   %Documents and Settings%\%current user%\Application Data\58685\58685.exe (519171 bytes)
   %Documents and Settings%\%current user%\Local Settings\Temp\58685.exe (781315 bytes)
   %Documents and Settings%\%current user%\Local Settings\Application Data\GDIPFONTCACHEV1.DAT (18432 bytes)
   %Documents and Settings%\%current user%\Local Settings\Temp\img_snapshot.exe (1263104 bytes)
   %Documents and Settings%\%current user%\Local Settings\Temp\uyrfg.png (143594 bytes)

4. Delete the following value(s) in the autorun key (How to Work with System Registry):

   [HKCU\Software\Microsoft\Windows\CurrentVersion\Run]
   "srvhosts" = "%Documents and Settings%\%current user%\Application Data\srvhosts1\srv.exe.exe"

5. Reboot the computer.
   

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

Static Analysis

VersionInfo

No information is available.

No information is available.

PE Sections

Name	Virtual Address	Virtual Size	Raw Size	Entropy	Section MD5
.text	8192	11156	11264	3.94803	d22c0ec9df09f47ea0b5789ed0805030
.sdata	24576	133	512	1.33153	efdf98cbec93a19bfa17303b5d8e62cd
.rsrc	32768	271846	271872	3.83993	72ef9b0f7e9cba1e321d24ed36e1a92d
.reloc	311296	12	512	0.056519	1b764c005bb6e335331f2c452e8258c4

Dropped from:

Downloaded by:

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Network Activity

URLs

IDS verdicts (Suricata alerts: Emerging Threats ET ruleset)

Traffic

Map

Strings from Dumps