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National Cyber
Awareness System:
07/01/2017 01:41 AM EDT
Original release date: July 01, 2017
| Last revised: July 28, 2017
Systems Affected
Microsoft
Windows operating systems
Overview
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 Alert’s 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] was notified of Petya malware events
occurring in multiple countries and affecting multiple sectors. This variant of
the Petya malware—referred to as NotPetya—encrypts 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:
Description
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 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 victim’s 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 victim’s ID, which means it may not be possible for the attacker to decrypt
the victim’s 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 and—in most cases—most effective method, uses a modified version of the
Mimikatz tool to steal the user’s 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 system’s 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 system’s 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 user’s 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 victim’s 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. Doc’s 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]
Impact
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 MS17‑010,
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 organization’s reputation.
Solution
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] 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://mischapuk6hyrn72[.]onion/
hxxp://petya3jxfp2f7g3i[.]onion/
hxxp://petya3sen7dyko2n[.]onion/
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]
- sid:2012063,
“ET NETBIOS Microsoft SRV2.SYS SMB Negotiate ProcessID? Function Table
Dereference (CVE-2009-3103)”[3]
- sid:2024297,
“ET CURRENT_EVENTS ETERNALBLUE Exploit M2 MS17-010”[4]
- sid:42944,"OS-WINDOWS
Microsoft Windows SMB remote code execution attempt"[11]
- sid:42340,"OS-WINDOWS
Microsoft Windows SMB anonymous session IPC share access attempt"[11]
- sid:41984,"OS-WINDOWS
Microsoft Windows SMBv1 identical MID and FID type confusion attempt"[11]
Recommended
Steps for Prevention
Review
US-CERT’s Alert on The Increasing Threat to Network Infrastructure Devices and
Recommended Mitigations [6], and consider implementing the
following best practices:
- Ensure
you have fully patched your systems, and confirm that you have applied
Microsoft’s patch for the MS17-010 SMB vulnerability dated March 14, 2017.[5]
- 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
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.
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