Dridex module leaks system info and potentially more. (Dec 11th, 2015)

The Dell Sonicwall UTM research team have discovered a Dridex info stealer module that leaks system information as well as potentially modifying certificates stored on the system.

Infection Cycle:

Upon infection the Trojan sends the following systen information to a remote C&C server:

The following encrypted conversation was then observed:

The Trojan drops the following file: 2FE.tmp.mod [Detected as GAV: Dridex.OOVO (Trojan)] on the infected system:

2FE.tmp.mod contains the following strings:

• Mozilla/4.0 (Mozilla/4.0; MSIE 7.0; Windows NT 5.1; FDM; SV1; .NET CLR 3.0.0

• CryptSIPDllGetSignedDataMsg
• CryptDllExportPublicKeyInfoEx
• CryptDllImportPublicKeyInfoEx
• CryptDllEncodePublicKeyAndParameters
• CryptDllConvertPublicKeyInfo
• CertDllVerifyRevocation
• CertDllVerifyCTLUsage
• CertDllOpenSystemStoreProv
• CertDllRegisterSystemStore
• CertDllUnregisterSystemStore
• CertDllEnumSystemStore
• CertDllRegisterPhysicalStore
• CertDllUnregisterPhysicalStore
• CertDllEnumPhysicalStore
• CryptDllExportPrivateKeyInfoEx
• CryptDllImportPrivateKeyInfoEx
• CertDllVerifyCertificateChainPolicy
• CryptMsgDllExportEncryptKey
• CryptMsgDllImportEncryptKey
• CryptMsgDllGenContentEncryptKey
• CryptMsgDllImportKeyTrans
• CryptMsgDllImportKeyAgree
• CryptMsgDllImportMailList

These strings suggest intent to inspect or manipulate certificates on the infected system.

On our infected test system the following data was encrypted an leaked to a C&C server:

SonicWALL Gateway AntiVirus provides protection against this threat via the following signatures:

• GAV: Dridex.AA_3 (Trojan)
• GAV: Dridex.OOVO (Trojan)

Security News

The SonicWall Capture Labs Threat Research Team gathers, analyzes and vets cross-vector threat information from the SonicWall Capture Threat network, consisting of global devices and resources, including more than 1 million security sensors in nearly 200 countries and territories. The research team identifies, analyzes, and mitigates critical vulnerabilities and malware daily through in-depth research, which drives protection for all SonicWall customers. In addition to safeguarding networks globally, the research team supports the larger threat intelligence community by releasing weekly deep technical analyses of the most critical threats to small businesses, providing critical knowledge that defenders need to protect their networks.