Executive Summary

Title Petya Ransomware
Name TA17-181A First vendor Publication 2017-07-01
Vendor US-CERT Last vendor Modification 2017-07-28
Severity (Vendor) N/A Revision N/A

Security-Database Scoring CVSS v3

Cvss vector : N/A
Overall CVSS Score NA
Base Score NA Environmental Score NA
impact SubScore NA Temporal Score NA
Exploitabality Sub Score NA
Calculate full CVSS 3.0 Vectors scores

Security-Database Scoring CVSS v2

Cvss vector : (AV:N/AC:L/Au:N/C:C/I:C/A:C)
Cvss Base Score 10 Attack Range Network
Cvss Impact Score 10 Attack Complexity Low
Cvss Expoit Score 10 Authentication None Required
Calculate full CVSS 2.0 Vectors scores


"This Alert has been updated to reflect the National Cybersecurity and Communications Integration Center's (NCCIC) analysis of the "NotPetya" malware variant."

The scope of this Alerts analysis is limited to the newest Petya malware variant that surfaced on June 27, 2017. This malware is referred to as NotPetya throughout this Alert.

On June 27, 2017, NCCIC [13] [ https://www.dhs.gov/national-cybersecurity-and-communications-integration-center ] was notified of Petya malware events occurring in multiple countries and affecting multiple sectors. This variant of the Petya malwarereferred to as NotPetyaencrypts files with extensions from a hard-coded list. Additionally, if the malware gains administrator rights, it encrypts the master boot record (MBR), making the infected Windows computers unusable. NotPetya differs from previous Petya malware primarily in its propagation methods.

The NCCIC Code Analysis Team produced a Malware Initial Findings Report (MIFR) to provide in-depth technical analysis of the malware. In coordination with public and private sector partners, NCCIC is also providing additional indicators of compromise (IOCs) in comma-separated-value (CSV) form for information sharing purposes.

Available Files:

* MIFR-10130295.pdf [ https://www.us-cert.gov/sites/default/files/publications/MIFR-10130295.pdf ]
* MIFR-10130295_stix.xml [ https://www.us-cert.gov/sites/default/files/publications/MIFR-10130295_stix.xml ]
* TA-17-181B_IOCs.csv [ https://www.us-cert.gov/sites/default/files/publications/TA-17-181B_IOCs.csv ]


NotPetya leverages multiple propagation methods to spread within an infected network. According to malware analysis, NotPetya attempts the lateral movement techniques below:

* PsExec - a legitimate Windows administration tool
* WMI - Windows Management Instrumentation, a legitimate Windows component
* EternalBlue - the same Windows SMBv1 exploit used by WannaCry
* EternalRomance - another Windows SMBv1 exploit

Microsoft released a security update for the MS17-010 [ https://technet.microsoft.com/library/security/MS17-010 ] SMB vulnerability on March 14, 2017, which addressed the EternalBlue and EternalRomance lateral movement techniques.

*Technical Details*

NCCIC received a sample of the NotPetya malware variant and performed a detailed analysis. Based on the analysis, NotPetya encrypts the victims files with a dynamically generated, 128-bit key and creates a unique ID of the victim. However, there is no evidence of a relationship between the encryption key and the victims ID, which means it may not be possible for the attacker to decrypt the victims files even if the ransom is paid. It behaves more like destructive malware rather than ransomware.

NCCIC observed multiple methods used by NotPetya to propagate across a network. The first andin most casesmost effective method, uses a modified version of the Mimikatz tool to steal the users Windows credentials. The cyber threat actor can then use the stolen credentials, along with the native Windows Management Instrumentation Command Line (WMIC) tool or the Microsoft SysInternals utility, psexec.exe, to access other systems on the network. Another method for propagation uses the EternalBlue exploit tool to target unpatched systems running a vulnerable version of SMBv1. In this case, the malware attempts to identify other hosts on the network by checking the compromised systems IP physical address mapping table. Next, it scans for other systems that are vulnerable to the SMB exploit and installs the malicious payload. Refer to the malware report, MIFR-10130295, for more details on these methods.

The analyzed sample of NotPetya encrypts the compromised systems files with a 128-bit Advanced Encryption Standard (AES) algorithm during runtime. The malware then writes a text file on the C:\ drive that includes a static Bitcoin wallet location as well as unique personal installation key intended for the victim to use when making the ransom payment and the users Bitcoin wallet ID. NotPetya modifies the master boot record (MBR) to enable encryption of the master file table (MFT) and the original MBR, and then reboots the system. Based on the encryption methods used, it appears unlikely that the files could be restored, even if the attacker received the victims unique key and Bitcoin wallet ID.

The delivery mechanism of NotPetya during the June 27, 2017, event was determined to be the Ukrainian tax accounting software, M.E.Doc. The cyber threat actors used a backdoor to compromise M.E. Docs development environment as far back as April 14, 2017. This backdoor allowed the threat actor to run arbitrary commands, exfiltrate files, and download and execute arbitrary exploits on the affected system. Organizations should treat systems with M.E.Doc installed as suspicious, and should examine these systems for additional malicious activity. [12] [ http://blog.talosintelligence.com/2017/07/the-medoc-connection.html ]


According to multiple reports, this NotPetya malware campaign has infected organizations in several sectors, including finance, transportation, energy, commercial facilities, and healthcare. While these victims are business entities, other Windows systems are also at risk, such as:

* those that do not have patches installed for the vulnerabilities in MS17010, CVE-2017-0144, and CVE-2017-0145, and
* those who operate on the shared network of affected organizations.

Negative consequences of malware infection include:

* temporary or permanent loss of sensitive or proprietary information,
* disruption to regular operations,
* financial losses incurred to restore systems and files, and
* potential harm to an organizations reputation.


NCCIC recommends against paying ransoms; doing so enriches malicious actors while offering no guarantee that the encrypted files will be released. In this NotPetya incident, the email address for payment validation was shut down by the email provider, so payment is especially unlikely to lead to data recovery.[1] [ https://www.bleepingcomputer.com/news/security/email-provider-shuts-down-petya-inbox-preventing-victims-from-recovering-files/ ] According to one NCCIC stakeholder, the sites listed below sites are used for payment in this activity. These sites are not included in the CSV package as IOCs.

hxxp://mischa5xyix2mrhd[.]onion/MZ2MMJ hxxp://mischapuk6hyrn72[.]onion/MZ2MMJ hxxp://petya3jxfp2f7g3i[.]onion/MZ2MMJ hxxp://petya3sen7dyko2n[.]onion/MZ2MMJ

*Network Signatures*

NCCIC recommends that organizations coordinate with their security vendors to ensure appropriate coverage for this threat. Given the overlap of functionality and the similarity of behaviors between WannaCry and NotPetya, many of the available rulesets can protect against both malware types when appropriately implemented. The following rulesets provided in publically available sources may help detect activity associated with these malware types:

* sid:2001569, ET SCAN Behavioral Unusual Port 445 traffic Potential Scan or Infection[2] [ http://doc.emergingthreats.net/2001569 ]
* sid:2012063, ET NETBIOS Microsoft SRV2.SYS SMB Negotiate ProcessID? Function Table Dereference (CVE-2009-3103)[3] [ http://doc.emergingthreats.net/bin/view/Main/2012063 ]
* sid:2024297, ET CURRENT_EVENTS ETERNALBLUE Exploit M2 MS17-010[4] [ http://docs.emergingthreats.net/bin/view/Main/2024297 ]
* sid:42944,"OS-WINDOWS Microsoft Windows SMB remote code execution attempt"[11] [ http://blog.talosintelligence.com/2017/06/worldwide-ransomware-variant.html ]
* sid:42340,"OS-WINDOWS Microsoft Windows SMB anonymous session IPC share access attempt"[11] [ http://blog.talosintelligence.com/2017/06/worldwide-ransomware-variant.html ]
* sid:41984,"OS-WINDOWS Microsoft Windows SMBv1 identical MID and FID type confusion attempt"[11] [ http://blog.talosintelligence.com/2017/06/worldwide-ransomware-variant.html ]

*Recommended Steps for Prevention*

Review US-CERTs Alert on The Increasing Threat to Network Infrastructure Devices and Recommended Mitigations [6] [ https://www.us-cert.gov/ncas/alerts/TA16-250A ], and consider implementing the following best practices:

* Ensure you have fully patched your systems, and confirm that you have applied Microsofts patch for the MS17-010 SMB vulnerability dated March 14, 2017.[5] [ https://technet.microsoft.com/library/security/MS17-010 ]
* Conduct regular backups of data and test your backups regularly as part of a comprehensive disaster recovery plan.
* Ensure anti-virus and anti-malware solutions are set to automatically conduct regular scans.
* Manage the use of privileged accounts. Implement the principle of least privilege. Do not assign administrative access to users unless absolutely needed. Those with a need for administrator accounts should only use them when necessary.
* Configure access controls, including file, directory, and network share permissions with the principle of least privilege in mind. If a user only needs to read specific files, they should not have write access to those files, directories, or shares.
* Secure use of WMI by authorizing WMI users and setting permissions.
* Utilize host-based firewalls and block workstation-to-workstation communications to limit unnecessary lateral communications.
* Disable or limit remote WMI and file sharing.
* Block remote execution through PSEXEC.
* Segregate networks and functions.
* Harden network devices and secure access to infrastructure devices.
* Perform out-of-band network management.
* Validate integrity of hardware and software.
* Disable SMBv1 and block all versions of SMB at the network boundary by blocking TCP port 445 with related protocols on UDP ports 137-138 and TCP port 139; this applies to all boundary devices.

*"Note:"*" Disabling or blocking SMB may create problems by obstructing access to shared files, data, or devices. Weigh the benefits of mitigation against potential disruptions to users."

*Recommended Steps for Remediation*

* NCCIC strongly encourages organizations contact a local Federal Bureau of Investigation (FBI) field office upon discovery to report an intrusion and request assistance. Maintain and provide relevant logs.
* Implement a security incident response and business continuity plan. Ideally, organizations should ensure they have appropriate backups so their response is simply to restore the data from a known clean backup.

*Report Notice*

DHS encourages recipients who identify the use of tools or techniques discussed in this document to report information to DHS or law enforcement immediately. To request incident response resources or technical assistance, contact NCCIC at NCCICcustomerservice@hq.dhs.gov [ https://www.us-cert.govmailto:NCCICcustomerservice@hq.dhs.gov ]or 888-282-0870. You can also report cyber crime incidents to the Internet Crime Complaint Center (IC3) at https://www.ic3.gov/default.aspx.

Original Source

Url : http://www.us-cert.gov/ncas/alerts/TA17-181A

CWE : Common Weakness Enumeration

% Id Name
67 % CWE-20 Improper Input Validation
33 % CWE-399 Resource Management Errors

OVAL Definitions

Definition Id: oval:org.mitre.oval:def:6489
Oval ID: oval:org.mitre.oval:def:6489
Title: SMBv2 Negotiation Vulnerability
Description: Array index error in the SMBv2 protocol implementation in srv2.sys in Microsoft Windows Vista Gold, SP1, and SP2, Windows Server 2008 Gold and SP2, and Windows 7 RC allows remote attackers to execute arbitrary code or cause a denial of service (system crash) via an & (ampersand) character in a Process ID High header field in a NEGOTIATE PROTOCOL REQUEST packet, which triggers an attempted dereference of an out-of-bounds memory location, aka "SMBv2 Negotiation Vulnerability." NOTE: some of these details are obtained from third party information.
Family: windows Class: vulnerability
Reference(s): CVE-2009-3103
Version: 3
Platform(s): Microsoft Windows Vista
Microsoft Windows Server 2008
Product(s): SMBv2
Definition Synopsis:

CPE : Common Platform Enumeration

Application 1
Os 7
Os 5

SAINT Exploits

Description Link
Windows SMB PsImpersonateClient null token vulnerability More info here
Windows SMB2 buffer overflow More info here

OpenVAS Exploits

Date Description
2009-10-15 Name : Microsoft Windows SMB2 Negotiation Protocol Remote Code Execution Vulnerability
File : nvt/secpod_ms09-050-remote.nasl
2009-10-01 Name : Microsoft Windows SMB2 '_Smb2ValidateProviderCallback()' Remote Code Executio...
File : nvt/ms_smb2_highid.nasl

Open Source Vulnerability Database (OSVDB)

Id Description
57799 Microsoft Windows srv2.sys Kernel Driver SMB2 Malformed NEGOTIATE PROTOCOL RE...

Microsoft Windows contains a flaw that may allow a malicious user to execute arbitrary code. The issue is triggered when a malicious user sends a specially crafted NEGOTIATE PROTOCOL REQUEST SMBv2 packet with an & (ampersand) character in a Process ID High header field, causing an attempted dereference of an out-of-bounds memory location. It is possible that the flaw may allow arbitrary code execution resulting in a loss of integrity.

Snort® IPS/IDS

Date Description
2017-05-23 Microsoft Windows SMB remote code execution attempt
RuleID : 42944-community - Revision : 2 - Type : OS-WINDOWS
2017-06-20 Microsoft Windows SMB remote code execution attempt
RuleID : 42944 - Revision : 2 - Type : OS-WINDOWS
2017-05-23 Microsoft Windows SMBv1 WriteAndX and TransSecondaryRequest TotalDataCount ou...
RuleID : 42294 - Revision : 2 - Type : OS-WINDOWS
2017-04-19 Microsoft Windows SMB remote code execution attempt
RuleID : 41978-community - Revision : 5 - Type : OS-WINDOWS
2017-04-12 Microsoft Windows SMB remote code execution attempt
RuleID : 41978 - Revision : 5 - Type : OS-WINDOWS
2014-01-10 Microsoft Windows SMB malformed process ID high field denial of service attempt
RuleID : 26643 - Revision : 6 - Type : OS-WINDOWS
2014-01-10 Microsoft Windows SMB malformed process ID high field remote code execution a...
RuleID : 15930 - Revision : 23 - Type : OS-WINDOWS

Nessus® Vulnerability Scanner

Date Description
2017-03-20 Name : The remote Windows host is affected by multiple vulnerabilities.
File : ms17-010.nasl - Type : ACT_GATHER_INFO
2017-03-15 Name : The remote Windows host is affected by multiple vulnerabilities.
File : smb_nt_ms17-010.nasl - Type : ACT_GATHER_INFO
2009-10-13 Name : The remote SMB server can be abused to execute code remotely.
File : smb_nt_ms09-050.nasl - Type : ACT_GATHER_INFO
2009-09-08 Name : Arbitrary code may be executed on the remote host through the SMB port
File : smb2_pid_high_vuln.nasl - Type : ACT_ATTACK

Alert History

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Date Informations
2017-07-29 00:21:48
  • Multiple Updates
2017-07-01 09:22:48
  • First insertion