Registration is now open for SASE Week 2023! Get on the guest list.

  • Security Service Edge Products

    Protect against advanced and cloud-enabled threats and safeguard data across all vectors.

  • Borderless SD-WAN

    Confidently provide secure, high-performance access to every remote user, device, site, and cloud.

The platform of the future is Netskope

Intelligent Security Service Edge (SSE), Cloud Access Security Broker (CASB), Cloud Firewall, Next Generation Secure Web Gateway (SWG), and Private Access for ZTNA built natively into a single solution to help every business on its journey to Secure Access Service Edge (SASE) architecture.

Go to Products Overview
Netskope video
Borderless SD-WAN: Ushering in the New Era of Borderless Enterprise

Netskope Borderless SD-WAN offers an architecture that converges zero trust principles and assured application performance to provide unprecedented secure, high-performance connectivity for every site, cloud, remote user, and IoT device.

Read the article
Borderless SD-WAN
  • NewEdge

    NewEdge is the world’s largest, highest-performing security private cloud.

  • Cloud Security Platform

    Unrivaled visibility and real-time data and threat protection on the world's largest security private cloud.

  • Technology Partners & Integrations

    Netskope partners with the strongest companies in enterprise technology.

Embrace a Secure Access Service Edge (SASE) architecture

Netskope NewEdge is the world’s largest, highest-performing security private cloud and provides customers with unparalleled service coverage, performance and resilience.

Learn about NewEdge
Your Network of Tomorrow

Plan your path toward a faster, more secure, and more resilient network designed for the applications and users that you support.

Get the white paper
Your Network of Tomorrow
Netskope Cloud Exchange

The Netskope Cloud Exchange (CE) provides customers with powerful integration tools to leverage investments across their security posture.

Learn about Cloud Exchange
Netskope video
Make the move to market-leading cloud security services with minimal latency and high reliability.

Learn about NewEdge
Lighted highway through mountainside switchbacks
Safely enable the use of generative AI applications with application access control, real-time user coaching, and best-in-class data protection.

Learn how we secure generative AI use
Safely Enable ChatGPT and Generative AI
Zero trust solutions for SSE and SASE deployments

Learn about Zero Trust
Boat driving through open sea
Netskope enables a safe, cloud-smart, and fast journey to adopt cloud services, apps, and public cloud infrastructure.

Learn about Industry Solutions
Wind turbines along cliffside
  • Resources

    Learn more about how Netskope can help you secure your journey to the cloud.

  • Blog

    Learn how Netskope enables security and networking transformation through security service edge (SSE).

  • Events & Workshops

    Stay ahead of the latest security trends and connect with your peers.

  • Security Defined

    Everything you need to know in our cybersecurity encyclopedia.

Security Visionaries Podcast

Leveling Up the SASE Conversation
Robert Arandjelovic and Gerry Plaza sit down to chat with Max Havey about how embracing a SASE journey can help bring networking and security teams closer together.

Play the podcast
Leveling Up the SASE Conversation
Latest Blogs

How Netskope can enable the Zero Trust and SASE journey through security service edge (SSE) capabilities.

Read the blog
Sunrise and cloudy sky
SASE Week 2023: Your SASE journey starts now!

Join us for the fourth annual SASE Week, September 26-28.

Get on the guest list
SASE Week 2023
What is Security Service Edge?

Explore the security side of SASE, the future of network and protection in the cloud.

Learn about Security Service Edge
Four-way roundabout
  • Our Customers

    Netskope serves more than 2,000 customers worldwide including more than 25 of the Fortune 100

  • Customer Solutions

    We are here for you and with you every step of the way, ensuring your success with Netskope.

  • Netskope Community

    Learn from other network, data, and security professionals.

  • Training and Certification

    Netskope training will help you become a cloud security expert.

We help our customers to be Ready for Anything

See our Customers
Woman smiling with glasses looking out window
Netskope’s talented and experienced Professional Services team provides a prescriptive approach to your successful implementation.

Learn about Professional Services
Netskope Professional Services
The Netskope Community can help you and your team get more value out of products and practices.

Go to the Netskope Community
The Netskope Community
Secure your digital transformation journey and make the most of your cloud, web, and private applications with Netskope training.

Learn about Training and Certifications
Group of young professionals working
  • Company

    We help you stay ahead of cloud, data, and network security challenges.

  • Why Netskope

    Cloud transformation and work from anywhere have changed how security needs to work.

  • Leadership

    Our leadership team is fiercely committed to doing everything it takes to make our customers successful.

  • Partners

    We partner with security leaders to help you secure your journey to the cloud.

Supporting sustainability through data security

Netskope is proud to participate in Vision 2045: an initiative aimed to raise awareness on private industry’s role in sustainability.

Find out more
Supporting Sustainability Through Data Security
Highest in Execution. Furthest in Vision.

Netskope recognized as a Leader in the 2023 Gartner® Magic Quadrant™ for Security Service Edge.

Get the report
Netskope recognized as a Leader in the 2023 Gartner® Magic Quadrant™ for Security Service Edge.
Thinkers, builders, dreamers, innovators. Together, we deliver cutting-edge cloud security solutions to help our customers protect their data and people.

Meet our team
Group of hikers scaling a snowy mountain
Netskope’s partner-centric go-to-market strategy enables our partners to maximize their growth and profitability while transforming enterprise security.

Learn about Netskope Partners
Group of diverse young professionals smiling

Ongoing email campaign spreading GlobeImposter Ransomware

Sep 05 2017
Cloud Security
Netskope Threat Research Labs

Last week, Netskope Threat Research Labs blogged about the resurgence of Locky Ransomware encrypting files to the LUKITUS extension. Since then, we have seen a surge of spam emails delivering several types of ransomware including Locky on a daily basis. While tracking the campaigns, Netskope Threat Research Labs observed over 600+ spam emails delivering GlobeImposter ransomware that encrypts the victim’s files and adds  “..txt” extensions. Netskope detects the malicious VBS file as “Backdoor.VB.downloadr.adr” and the payload as “Backdoor.generckd.5942787” respectively.

Spam Campaign

The attackers behind this campaign crafted spam emails by not only attaching a malicious archive file but also inserting a malicious link inside the email body. The attachment contains malicious VBScript code which downloads the ransomware payload, similar to the delivery mechanism of Locky ransomware. An example of the spam email spreading GlobeImposter Ransomware is shown in Figure 1.

Figure 1: Spam email spreading GlobeImposter Ransomware.

As shown in Figure 1, the email has an attachment with the name “Invoice INV-000993.7z” which contains malicious VBScript named “INV-000695.vbs” which on execution downloads GlobeImposter ransomware. The attacker deliberately included a malicious link along with the attachment. This tactic was employed as an alternate measure to make the victim click the hyperlink in case the attachments were detected by the security solution. Hovering over the hyperlinks from the spam email we analyzed revealed the malicious URL downloading a similar 7-ZIP file as shown in Figure 2.

Figure 2: Email not only contains attachment but also includes a malicious link.

At the time of writing this blog, the malicious link was down.

Analysis of the VBScript

As mentioned earlier, the 7-ZIP archives contain a malicious VBScript code as shown in Figure 3.

Figure 3: Malicious script code to download and execute GlobeImposter.

As shown in Figure 3, an interesting point to note is that the attackers have named the variables on a character from the famous Game of Thrones television series. This malicious code first downloads the encrypted payload from the attacker’s controlled or compromised domain as shown in Figure 4.

Figure 4: Malicious script downloading encrypted payload.

The encrypted payload is downloaded in %TEMP% folder with a random name and “.exeA” extension, for example, inCzr.exeA. The VBScript then decrypts this custom encrypted payload using XOR  into an executable file (removing A from .exe extension) as shown in Figure 5.

Figure 5: Payloads saved and executed from %TEMP% folder.

The encrypted and decrypted version of the payload is as shown in Figure 6.

Figure 6: Encrypted and decrypted ransomware payloads.

The decrypted GlobeImposter ransomware executable then infects the victim’s machine and starts encrypting victim’s files.

The executed payload also drops Windows batch (.bat) file with the name “__t7609.tmp.bat” under %TEMP% folder that deletes shadow copies along with some registry keys. The activity performed by this batch file looks as shown in Figure 7.

Figure 7: Dropped batch file.

The working summary of the batch file is as follows,

  1. Deletes shadow copies from the system using vssadmin.exe. This makes the recovery of encrypted files from the victim’s system impossible.
  2. Delete registry key HKEY_CURRENT_USER\Software\Microsoft\Terminal Server Client\Default which contains the list of 10 RDP servers that have been recently used (MRU means Most Recently Used).
  3. Delete registry key HKEY_CURRENT_USER\Software\Microsoft\Terminal Server Client\Servers. It contains the list of all RDC (remote desktop client) connections that have ever been established from this computer.
  4. Add registry key HKEY_CURRENT_USER\Software\Microsoft\Terminal Server Client\Servers again.
  5. Change the Default.rdp file attributes, by default it is Hidden and System.
  6. Delete the file Default.rdp file.
  7. Lastly, clear event logs using the wevtutil command

This variant of GlobeImposter excludes certain folders and file extensions from being encrypted. The list of 45 excluded folders is shown below:

“Windows, Microsoft, Microsoft Help, Windows App Certification Kit, Windows Defender, ESET, COMODO, Windows NT, Windows Kits, Windows Mail, Windows Media, Player, Windows Multimedia Platform, Windows Phone Kits, Windows Phone Silverlight Kits, Windows Photo Viewer, Windows Portable Devices, Windows, Sidebar, WindowsPowerShell, Temp, NVIDIA Corporation, Microsoft.NET, Internet Explorer, Kaspersky Lab, McAfee, Avira, spytech software, sysconfig, Avast, Dr.Web, Symantec, Symantec_Client_Security, system volume information, Microsoft Shared, Common Files, Outlook Express, Movie Maker, Chrome, Mozilla Firefox, Opera, YandexBrowser, ntldr, Wsus, ProgramData”

The list of 160 excluded extensions is shown below:

“.$er, .4db, .4dd, .4mp, .abs, .abx, .accdb, .accdc, .accde, .accdr, .accdt, .accdw, .accft, .adn, .adp, .aft, .ahd, .alf, .ask, .awdb, .azz, .bdb, .bib, .bnd, .bok, .btr, .cdb, .cdb, .cdb, .ckp, .clkw, .cma, .crd, .daconnections, .dacpac, .dad, .dadiagrams, .daf, .daschema, .db-shm, .db-wa, .db2, .db3, .dbc, .dbf, .dbf, .dbk, .dbs, .dbt, .dbv, .dbx, .dcb, .dct, .dcx, .df1, .dmo, .dnc, .dp1, .dqy, .dsk, .dsn, .dta, .dtsx, .eco, .ecx, .edb, .emd, .fcd, .fdb, .fic, .fid, .fm5, .fmp, .fmp12, .fmps, .fp3, .fp4, .fp5, .fp7, .fpt, .fzb, .fzv, .gdb, .gwi, .hdb, .his, .idc, .ihx, .itdb, .itw, .jtx, .kdb, .lgc, .maq, .mdb, .mdbhtm, .mdf, .mdn, .mdt, .mrg, .mud, .mwb, .myd, .ndf, .ns2, .ns3, .ns4, .nsf, .nv2, .nyf, .oce, .odb, .oqy, .ora, .orx, .owc, .owg, .oyx, .p96, .p97, .pan, .pdb, .pdm, .phm, .pnz, .pth, .pwa, .qpx, .qry, .qvd, .rctd, .rdb, .rpd, .rsd, .sbf, .sdb, .sdf, .spq, .sqb, .sqlite, .sqlite3, .sqlitedb, .str, .tcx, .tdt, .teacher, .tmd, .trm, .udb, .usr, .v12, .vdb, .vpd, .wdb, .wmdb, .xdb, .xld, .xlgc, .zdb, .zdc”

As mentioned earlier, this GlobeImposter Ransomware encrypts the files that are not in the excluded extension list with “..txt” extensions as shown in Figure 8.

Figure 8: GlobeImposter encrypted files with ..txt extension.

GlobeImposter also drops “Read_ME.html” ransom warning file on the desktop as well individual directories which displays a warning as shown in Figure 9.

Figure 9: GlobeImposter warning message.

Upon entering the details and clicking on the ‘Buy Decryptor’ button, the victim is directed to another website which demands a payment of 0.233 Bitcoin as shown in Figure 10.

Figure 10: GlobeImposter Ransomware payment page for recovery.

As mentioned in Figure 10, GlobeImposter demands the victim pay the Ransom within an offer period of 2 days. After this, the Ransom is doubled to 0.466 Bitcoin. An option to decrypt one encrypted file is also provided.


We continue to see a rise in the number of email campaigns delivering ransomware. Locky continued to be dominant amongst several types of ransomware, but attackers behind other ransomware like GlobeImposter have also started picking up. The usage of hyperlinks and email attachments to invoke a successful install of the ransomware clearly states that email continues to be the extensively used attack vector. Netskope Threat Research Labs will continue monitoring the ransomware spam email campaigns, the evolution of ransomware strains and report the use of any new techniques and evasions.

General Recommendations

Netskope recommends the following to combat cloud malware and threats:

  • Detect and remediate cloud threats using a threat-aware CASB like and enforce policy on usage of unsanctioned services as well as unsanctioned instances of sanctioned cloud services
  • Sample policies to enforce:
    • Scan all uploads from unmanaged devices to sanctioned cloud services for malware
    • Scan all uploads from remote devices to sanctioned cloud  services for malware
    • Scan all downloads from unsanctioned cloud  services for malware
    • Scan all downloads from unsanctioned instances of sanctioned cloud  services for malware
    • Enforce quarantine/block actions on malware detection to reduce user impact
    • Block unsanctioned instances of sanctioned/well-known cloud services, to prevent attackers from exploiting user trust in the cloud. While this seems a little restrictive, it significantly reduces the risk of malware infiltration attempts via cloud
  • Enforce DLP policies to control files and data en route to or from your corporate environment
  • Regularly back up and turn on versioning for critical content in cloud services
  • Enable the “View known file extensions” option on Windows machines
  • Warn users to avoid executing unsigned macros and macros from an untrusted source, unless they are very sure that they are benign
  • Warn users to avoid executing any file unless they are very sure that they are benign
  • Warn users against opening untrusted attachments, regardless of their extensions or filenames
  • Keep systems and antivirus updated with the latest releases and patches

Stay informed!

Subscribe for the latest from the Netskope Blog