Concrete signature match: Password Stealer - Steals credentials and sensitive information for 32-bit Windows platform, family Dyzap
PWS:Win32/Dyzap.A is a concrete detection for a component of the Dyzap malware family, strongly associated with the notorious Dyreza banking Trojan. This threat is designed to steal sensitive information, including credentials, through techniques like browser injection and network interception, and communicates with command-and-control servers for data exfiltration and further instructions.
Relevant strings associated with this threat: - \DYRE\Release\zapuskator (PEHSTR_EXT) - AUTOBACKCONN (PEHSTR_EXT) - =RBSG_CORP4P&domain= (PEHSTR_EXT) - </rpci> (PEHSTR_EXT) - send browsnapshot failed (PEHSTR_EXT) - /%s/%s/%d/%s/%s/ (PEHSTR_EXT) - \DYRE\x64\Release\dyrecontroller.pdb (PEHSTR_EXT) - /%s/%s/5/publickey/ (PEHSTR_EXT)
rule PWS_Win32_Dyzap_A_2147687905_0
{
meta:
author = "threatcheck.sh"
detection_name = "PWS:Win32/Dyzap.A"
threat_id = "2147687905"
type = "PWS"
platform = "Win32: Windows 32-bit platform"
family = "Dyzap"
severity = "Critical"
signature_type = "SIGNATURE_TYPE_PEHSTR_EXT"
threshold = "4"
strings_accuracy = "High"
strings:
$x_1_1 = "\\DYRE\\Release\\zapuskator" ascii //weight: 1
$x_1_2 = ".\\pipe\\RangisPipe" wide //weight: 1
$x_1_3 = "AUTOBACKCONN" ascii //weight: 1
$x_1_4 = "=RBSG_CORP4P&domain=" ascii //weight: 1
$x_1_5 = {48 83 ec 20 ff 55 08 48 8b 4d cc 48 8d 64 cc 20 5f 48 89 45 f4 e8 00 00 00 00 c7 44 24 04 23 00 00 00 83 04 24 0d cb} //weight: 1, accuracy: High
condition:
(filesize < 20MB) and
(4 of ($x*))
}10745182ac1b738e4a363166f650069d16b81873b3bbb1990e7d07cb652495e8Immediately isolate the infected system. Perform a full system scan with updated antivirus software, ensuring all malicious files are quarantined or removed. Investigate for persistence mechanisms, command-and-control communication, and potential data exfiltration. Reset all compromised credentials, especially banking, corporate, and sensitive online accounts. Consider a system reimage if complete eradication cannot be confirmed.