Ransomware Research

STOP Ransomware

STOP is a malicious ransomware strain that encrypts victim files and demands ransom payment for decryption. First observed in the wild on December 1, 2017, this ransomware has been actively targeting systems worldwide. Security researchers also track this malware under the aliases: STOP-Keypass, STOP-Djvu, Djvu.

Quick facts

Ransomware Family
STOP
First Seen
December 1, 2017
Known Aliases
STOP-KeypassSTOP-DjvuDjvu

How STOP ransomware works

File encryption patterns

STOP modifies encrypted files using specific patterns to mark them as encrypted:

Extensions added after encryption
.STOP.promorad.DATASTOP.STOPDATA.KEYPASS.WHY.SAVEfiles.DATAWAIT.INFOWAIT.puma.pumax.pumas.shadow.djvu.jzeq.jzie.djvuu.udjvu.uudjvu.codnat.djvuq.djvus.djvur.djvut.djvup.pdff.tro.tfude.tfudeq.tfudet.rumba.adobe.adobee.blower.promos.promoz.promok.promorad2.kroput.kroput1.charck.pulsar1.klope.kropun.charcl.kropun1.doples.luces.luceq.chech.proden.drume.tronas.grovas.trosak.grovat.roland.refols.raldug.etols.guvara.browec.norvas.moresa.verasto.hrosas.kiratos.todarius.hofos.roldat.dutan.sarut.fedasot.berost.forasom.fordan.bufas.dotmap.radman.ferosas.rectot.skymap.mogera.rezuc.stone.redmat.lanset.davda.poret.pidon.heroset.boston.myskle.muslat.gerosan.vesad.horon.neras.truke.dalle.lotep.nusar.litar.besub.cezor.gycc.gyew.gyza.lokas.godes.budak.vusad.herad.berosuce.gehad.gusau.madek.tocue.darus.lapoi.todar.dodoc.bopador.novasof.ntuseg.ndarod.access.format.nelasod.mogranos.cosakos.nvetud.lotej.kovasoh.prandel.zatrov.masok.brusaf.londec.krusop.mtogas.nasoh.coharos.nacro.pedro.nuksus.vesrato.cetori.masodas.stare.carote.shariz.gero.hese.xoza.seto.peta.moka.meds.kvag.domn.karl.nesa.boot.noos.kuub.reco.bora.leto.nols.werd.coot.derp.nakw.meka.toec.mosk.lokf.peet.grod.mbed.kodg.zobm.rote.msop.hets.righ.gesd.merl.mkos.nbes.piny.redl.kodc.nosu.repp.alka.bboo.rooe.mmnn.ooss.mool.nppp.rezm.lokd.jazi.jawr.foop.remk.npsk.opqz.mado.jope.mpaj.lalo.lezp.qewe.mpal.sqpc.mzlq.koti.covm.pezi.nlah.kkll.zwer.nypd.usam.tabe.vawe.moba.pykw.zida.maas.repl.kuus.erif.kook.nile.oonn.vari.boop.geno.kasp.ogdo.npph.kolz.copa.lyli.moss.foqe.mmpa.efji.iiss.jdyi.vpsh.agho.vvoa.epor.sglh.lisp.weui.nobu.igdm.booa.omfl.igal.qlkm.coos.wbxd.pola.cosd.plam.ygkz.cadq.tirp.ribd.reig.enfp.ekvf.ytbn.fdcz.urnb.lmas.iicc.wrui.rejg.pcqq.igvm.nusm.ehiz.eqew.paas.pahd.mppq.qscx.sspq.iqll.ddsg.gatz.eqza.gash.qopz.qore.fofd.sato.saba.foty.foza.coty.kiop.kiwm.kifr.jycx.jypo.jywd.jyos.typo.tyos.tywd.darj.dapo.dazx.craa.qarj.qazx.qapo.coba.coaq.cosw.goba.goaq.gosw.qotr.qoqa.qowd.iotr.iowd.ioqa.hhoo.hhee.hhmm.tgvv.tgpo.thgz.bhgr.bhui.bhtw.ahtw.ahgr.ahui.neqp.neon.nerz.erqw.assm.mztu.mzop.mzqw.pouu.poqw.zouu.zoqw.bpto.bpws.bpsm.znto.taqw.taoy.tasa.yytw.yyza.popn.poaz.wspn.wsaz.wsuu.kitu.kizu.kiqu.miqe.mitu.miza.gaqq.waqq.gazp.gayn.wazp.wayn.agvv.agpo.aghz.vvoo.vvmm.erop.weqp.werz.weon.vatq.vaze.vapo.gaze.gatq.gapo.xaro.xatz.xash.nzoq.teza.nzqw.nztt.wzer.wzoq.wztt.wzqw.jaqw.jaoy.jasa.mzre.mzqt.mzhi.azop.azqt.azhi.wwty.wwpl.wwza.oohu.oopl.ooza.hgew.hgfu.hgml.hgkd.rzew.rzml.rzkd.ttwq.ttrd.ttap.ttza.mlwq.mlrd.mlap.mlza.ptqw.pthh.ptrz.ithh.itqw.itrz.zpas.zput.zpww.ppvs.ppvt.ppvw.yzqe.yzoo.yzaq.nbzi.hhuy.hhaz.ljuy.ljaz.nbwr.niwm.cdqw.cdmx.cdaz.cdwe.cdtt.cdpo.cdcc.ldhy.cdxx.nooa.qqqe.iisa.wnlu.hoop.pqgs.orkf.koom.bbbw.bbbe.cuag.bbbr.yoqs.stax.eucy.nqhd.maiv.lkfr.lkhy.muuq.miia.irjg.rtgf.qqqw.moia.zaps.aeur.cool.wisz.wiaw.nood.looy.vook.kool.uazq.uajs.kaaa.bgjs.bgzq.qehu.qepi.vepi.vehu.paaa.qeza.veza.lqqw.xcmb.waqa.zzla.rivd.maql.tisc.nqsq.piiq.reqg.maak.vtua.guer.qmak.hlas.vfgj.neer.sevr.pooe.moqs.wiot.efdc.hgsh.ufwj.gujd.irfk.rigd.mmuz.udla.ttii.xcvf.voom.fgnh.rigj.sijr.bbnm.npsg.xcbg.gtys.fgui.hhjk.iiof.dewd.jhbg.qbaa.nuhb.dmay.egfg.mmob.bpqd.rguy.dwqs.wdlo.zqqw.ssoi.hajd.fefg.ifla

Ransom note and payment demands

After encrypting files, STOP displays ransom notes demanding payment for file recovery:

file!!!DATA_RESTORE!!!.txt
file!!!RESTORE_DATA!!!.txt
file!!!KEYPASS_DECRYPTION_INFO!!!.txt
file!!!DECRYPTION__KEYPASS__INFO!!!.txt
file!!!WHY_MY_FILES_NOT_OPEN!!!.txt
file!!!SAVE_FILES_INFO!!!.txt
file!readme.txt
notes/!readme.txt
Location: EveryFolder
file_openme.txt
notes/_openme.txt
Location: EveryFolder
file_readme.txt
notes/_readme.txt
Location: EveryFolder
file_open_.txt
file__readme.txt
file!!!YourDataRestore!!!.txt

Technical indicators

Associated executable files

The following executable files are associated with STOP ransomware:

Recovery and decryption tools

Decryption tools may be available for STOP. Review the resources below:

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About this analysis

This STOP ransomware analysis is part of Elastio's comprehensive ransomware detection database. Elastio provides advanced ransomware protection and recovery, helping organizations defend against and recover from ransomware attacks like STOP.

Last updated: December 30, 2025

Detection coverage

Elastio detects STOP inside your data and backups.

The Hunt Engine uses Deep File Inspection to identify STOP across live data, replicated data, and backups. If this family is in your environment, Elastio finds it before encryption completes. Run a scan against your recovery points to confirm.

See How the Hunt Engine WorksRequest a Demo

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