Concrete signature match: Trojan - Appears legitimate but performs malicious actions for 32-bit Windows platform, family Lazy
Trojan:Win32/Lazy.AB!MTB is a highly malicious Trojan detected via concrete signatures and behavioral analysis, indicating a low false positive risk. It extensively abuses legitimate Windows utilities like mshta, regsvr32, rundll32, and PowerShell, implements API hooking, creates scheduled tasks for persistence, and can perform remote file operations, aiming for comprehensive system control and malicious execution.
Relevant strings associated with this threat: - Fjiocoivjsfiiqwi (PEHSTR_EXT) - |#c1db55ab-c21a-4637-bb3f-a12568109d35 (NID) - }#c1db55ab-c21a-4637-bb3f-a12568109d35 (NID) - |#d4f940ab-401b-4efc-aadc-ad5f3c50688a (NID) - }#d4f940ab-401b-4efc-aadc-ad5f3c50688a (NID) - !#HSTR:StringCodeForMshta.A!pli (PEHSTR_EXT) - !#HSTR:StringCodeForHooking.C!pli (PEHSTR_EXT) - !#HSTR:StringCodeForHooking.D!pli (PEHSTR_EXT) - !#HSTR:StringCodeForHooking.L!pli (PEHSTR_EXT) - !#HSTR:StringCodeForHooking.O!pli (PEHSTR_EXT) - !#HSTR:StringCodeForRegsvr32.A!pli (PEHSTR_EXT) - !#HSTR:StringCodeForRundll32.A!pli (PEHSTR_EXT) - rundll32 (PEHSTR_EXT) - !#HSTR:StringCodeForBITSJobs.A!pli (PEHSTR_EXT) - !#HSTR:StringCodeForPowerShell.G!pli (PEHSTR_EXT) - !#HSTR:StringCodeForScheduledTask.A!pli (PEHSTR_EXT) - !#HSTR:StringCodeForDataEncoding.D!pli (PEHSTR_EXT) - !#HSTR:StringCodeForHooking.J!pli (PEHSTR_EXT) - !#HSTR:StringCodeForHooking.K!pli (PEHSTR_EXT) - !#HSTR:StringCodeForRemoteFileCopy.B!pli (PEHSTR_EXT) - !#HSTR:StringCodeForFileDeletion.A!pli (PEHSTR_EXT)
rule Trojan_Win32_Lazy_AB_2147849152_0
{
meta:
author = "threatcheck.sh"
detection_name = "Trojan:Win32/Lazy.AB!MTB"
threat_id = "2147849152"
type = "Trojan"
platform = "Win32: Windows 32-bit platform"
family = "Lazy"
severity = "Critical"
info = "MTB: Microsoft Threat Behavior"
signature_type = "SIGNATURE_TYPE_PEHSTR_EXT"
threshold = "10"
strings_accuracy = "High"
strings:
$x_10_1 = {83 7c 24 60 10 8d 44 24 4c 0f 43 44 24 4c 8a 04 10 2a 04 91 88 44 24 13 3b de 73 2e 8a 4c 24 13 8d 43 01 89 44 24 38 83 fe 10 8d 44 24 28 0f 43 c7 88 0c 18 c6 44 18 01 00 8b 74 24 3c 8b 5c 24 38 8b 7c 24 28} //weight: 10, accuracy: High
condition:
(filesize < 20MB) and
(all of ($x*))
}b0e1beb8efa31915bb0391e97993f6a6774feda87f1b61d67f9d3c8bb6308b12Immediately isolate the infected system. Perform a comprehensive antimalware scan and ensure all detected malicious files, scheduled tasks, and registry modifications are removed. Thoroughly investigate for any signs of lateral movement, data exfiltration, or further compromise, and restore the system from a trusted clean backup if necessary.