TROJ_KOVTER.AUSIO

March 01, 2017

ALIASES:

Trojan:Win32/Kovter (Microsoft); GenericR-JET!B38F9D4F29C7 (McAfee); Trojan.Kotver (Symantec); Trojan.Win32.Poweliks.mra (Kaspersky); Trojan.Win32.Generic!BT (Sunbelt); Trojan horse Atros4.CFND (AVG)

PLATFORM:

Windows

OVERALL RISK RATING:

DAMAGE POTENTIAL:

DISTRIBUTION POTENTIAL:

REPORTED INFECTION:

Threat Type: Trojan
Destructiveness: No
Encrypted:
In the wild: Yes

OVERVIEW

This Trojan arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.

It deletes itself after execution.

TECHNICAL DETAILS

File Size: 339,844 bytes

File Type: EXE

Memory Resident: No

Initial Samples Received Date: 01 Mar 2017

Arrival Details

This Trojan 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 creates the following folders:

%Application Data%\loge
%User Profile%\CryptnetUrlCache\MetaData
%User Profile%\Microsoft\CryptnetUrlCache
%User Profile%\CryptnetUrlCache\Content
%System Root%\_112203_
%System Root%\2df6916556b3249c5982fbd2e2de
%System Root%\2df6916556b3249c5982fbd2e2de\update

(Note: %Application Data% is the Application Data folder, where it usually is C:\Documents and Settings\{user name}\Application Data on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\AppData\Roaming 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.. %User Profile% is the current user's profile folder, which is usually C:\Documents and Settings\{user name} on Windows 2000, XP, and Server 2003, or C:\Users\{user name} on Windows Vista and 7.. %System Root% is the Windows root folder, where it usually is C:\ on all Windows operating system versions.)

Other System Modifications

This Trojan adds the following registry keys:

HKEY_CURRENT_USER\Software\Microsoft\
Internet Explorer\Main\FeatureControl

HKEY_CURRENT_USER\Software\Microsoft\
Internet Explorer\Main\FeatureControl\
FEATURE_BROWSER_EMULATION

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Internet Explorer\Main\FeatureControl\
FEATURE_BROWSER_EMULATION

HKEY_CURRENT_USER\Software\qanz

HKEY_LOCAL_MACHINE\SOFTWARE\qanz

HKEY_LOCAL_MACHINE\SOFTWARE\Policies\
Microsoft\Windows\WindowsUpdate\
OSUpgrade

HKEY_LOCAL_MACHINE\SOFTWARE\C7E8907B6AC14E45

HKEY_LOCAL_MACHINE\SOFTWARE\5DFAD47D3556F8EEDC

It adds the following registry entries:

HKEY_CURRENT_USER\Software\Microsoft\
Internet Explorer\Main\FeatureControl\
FEATURE_BROWSER_EMULATION
regsvr32.exe = "22b8"

HKEY_CURRENT_USER\Software\Microsoft\
Internet Explorer\Main\FeatureControl\
FEATURE_BROWSER_EMULATION
iexplore.exe = "22b8"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Internet Explorer\Main\FeatureControl\
FEATURE_BROWSER_EMULATION
regsvr32.exe = "22b8"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Internet Explorer\Main\FeatureControl\
FEATURE_BROWSER_EMULATION
iexplore.exe = "22b8"

HKEY_LOCAL_MACHINE\SOFTWARE\Policies\
Microsoft\Windows\WindowsUpdate
DisableOSUpgrade = "1"

HKEY_LOCAL_MACHINE\SOFTWARE\Policies\
Microsoft\Windows\WindowsUpdate\
OSUpgrade
ReservationsAllowed = "0"

HKEY_LOCAL_MACHINE\SOFTWARE\qanz
ltpxeirzlt = "Iz0WjJY7B2CJww=="

HKEY_CURRENT_USER\Software\qanz
ltpxeirzlt = "ImkXicAwBZ4dGg=="

HKEY_LOCAL_MACHINE\SOFTWARE\qanz
bjtkim = "JTkRiMAwAiCP2VZSeuHBSFQDvk+tl7I="

HKEY_CURRENT_USER\Software\qanz
bjtkim = "dzlCj5NsVN5/5RiaJ24jD5GGeWUKJAo="

HKEY_LOCAL_MACHINE\SOFTWARE\qanz
eljz = "cThM3pRrVOIxtY/LKOAJcLI="

HKEY_CURRENT_USER\Software\qanz
eljz = "eGpAi55sU0J2NStgV3bilj4="

HKEY_LOCAL_MACHINE\SOFTWARE\qanz
zojewbdazo = "{random characters}"

HKEY_CURRENT_USER\Software\qanz
zojewbdazo = "{random characters}"

HKEY_LOCAL_MACHINE\SOFTWARE\qanz
kqdg = "{random characters}"

HKEY_CURRENT_USER\Software\qanz
kqdg = "{random characters}"

HKEY_LOCAL_MACHINE\SOFTWARE\C7E8907B6AC14E45
F367930B6F17E3B2E5 = "F367930B6F17E3B2E5"

HKEY_LOCAL_MACHINE\SOFTWARE\5DFAD47D3556F8EEDC
B067898B15B669F8 = "B067898B15B669F8"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Setup
LogLevel = "2"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Setup
LogLevel = "0"

It modifies the following registry entries:

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Internet Settings\
Zones\3
1206 = "0"

(Note: The default value data of the said registry entry is 3.)

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Internet Settings\
Zones\3
2300 = "0"

(Note: The default value data of the said registry entry is 1.)

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Internet Settings\
Zones\3
1809 = "3"

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Internet Settings\
Zones\1
1206 = "0"

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Internet Settings\
Zones\1
2300 = "0"

(Note: The default value data of the said registry entry is 1.)

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Internet Settings\
Zones\1
1809 = "3"

(Note: The default value data of the said registry entry is 3.)

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
SystemCertificates\AuthRoot\Certificates\
4EFCED9C6BDD0C985CA3C7D253063C5BE6FC620C
Blob = "{random values}"