diff --git a/share/demo.kdbx b/share/demo.kdbx
index f78524633..35fd79ce1 100644
Binary files a/share/demo.kdbx and b/share/demo.kdbx differ
diff --git a/src/core/EntryAttachments.cpp b/src/core/EntryAttachments.cpp
index be8135f5f..1afb337ab 100644
--- a/src/core/EntryAttachments.cpp
+++ b/src/core/EntryAttachments.cpp
@@ -18,14 +18,25 @@
 #include "EntryAttachments.h"
 
 #include "core/Global.h"
+#include "crypto/Random.h"
 
+#include <QDesktopServices>
+#include <QDir>
+#include <QProcessEnvironment>
 #include <QSet>
+#include <QTemporaryFile>
+#include <QUrl>
 
 EntryAttachments::EntryAttachments(QObject* parent)
     : ModifiableObject(parent)
 {
 }
 
+EntryAttachments::~EntryAttachments()
+{
+    clear();
+}
+
 QList<QString> EntryAttachments::keys() const
 {
     return m_attachments.keys();
@@ -82,6 +93,10 @@ void EntryAttachments::remove(const QString& key)
 
     m_attachments.remove(key);
 
+    if (m_openedAttachments.contains(key)) {
+        disconnectAndEraseExternalFile(m_openedAttachments.value(key));
+    }
+
     emit removed(key);
     emitModified();
 }
@@ -92,20 +107,17 @@ void EntryAttachments::remove(const QStringList& keys)
         return;
     }
 
+    bool emitStatus = modifiedSignalEnabled();
+    setEmitModified(false);
+
     bool isModified = false;
     for (const QString& key : keys) {
-        if (!m_attachments.contains(key)) {
-            Q_ASSERT_X(
-                false, "EntryAttachments::remove", qPrintable(QString("Can't find attachment for key %1").arg(key)));
-            continue;
-        }
-
-        isModified = true;
-        emit aboutToBeRemoved(key);
-        m_attachments.remove(key);
-        emit removed(key);
+        isModified |= m_attachments.contains(key);
+        remove(key);
     }
 
+    setEmitModified(emitStatus);
+
     if (isModified) {
         emitModified();
     }
@@ -133,15 +145,47 @@ void EntryAttachments::clear()
 
     m_attachments.clear();
 
+    const auto externalPath = m_openedAttachments.values();
+    for (auto& path : externalPath) {
+        disconnectAndEraseExternalFile(path);
+    }
+
     emit reset();
     emitModified();
 }
 
+void EntryAttachments::disconnectAndEraseExternalFile(const QString& path)
+{
+    if (m_openedAttachmentsInverse.contains(path)) {
+        m_attachmentFileWatchers.value(path)->stop();
+        m_attachmentFileWatchers.remove(path);
+
+        m_openedAttachments.remove(m_openedAttachmentsInverse.value(path));
+        m_openedAttachmentsInverse.remove(path);
+    }
+
+    QFile f(path);
+    if (f.open(QFile::ReadWrite)) {
+        qint64 blocks = f.size() / 128 + 1;
+        for (qint64 i = 0; i < blocks; ++i) {
+            f.write(randomGen()->randomArray(128));
+        }
+        f.close();
+    }
+    f.remove();
+}
+
 void EntryAttachments::copyDataFrom(const EntryAttachments* other)
 {
     if (*this != *other) {
         emit aboutToBeReset();
 
+        // Reset all externally opened files
+        const auto externalPath = m_openedAttachments.values();
+        for (auto& path : externalPath) {
+            disconnectAndEraseExternalFile(path);
+        }
+
         m_attachments = other->m_attachments;
 
         emit reset();
@@ -167,3 +211,54 @@ int EntryAttachments::attachmentsSize() const
     }
     return size;
 }
+
+bool EntryAttachments::openAttachment(const QString& key, QString* errorMessage)
+{
+    if (!m_openedAttachments.contains(key)) {
+        const QByteArray attachmentData = value(key);
+        auto ext = key.contains(".") ? "." + key.split(".").last() : "";
+
+#ifdef KEEPASSXC_DIST_SNAP
+        const QString tmpFileTemplate =
+            QString("%1/XXXXXXXXXXXX%2").arg(QProcessEnvironment::systemEnvironment().value("SNAP_USER_DATA"), ext);
+#else
+        const QString tmpFileTemplate = QDir::temp().absoluteFilePath(QString("XXXXXXXXXXXX").append(ext));
+#endif
+
+        QTemporaryFile tmpFile(tmpFileTemplate);
+
+        const bool saveOk = tmpFile.open() && tmpFile.setPermissions(QFile::ReadOwner | QFile::WriteOwner)
+                            && tmpFile.write(attachmentData) == attachmentData.size() && tmpFile.flush();
+
+        if (!saveOk && errorMessage) {
+            *errorMessage = tr("%1 - %2").arg(key, tmpFile.errorString());
+            return false;
+        }
+
+        tmpFile.close();
+        tmpFile.setAutoRemove(false);
+        m_openedAttachments.insert(key, tmpFile.fileName());
+        m_openedAttachmentsInverse.insert(tmpFile.fileName(), key);
+
+        auto watcher = QSharedPointer<FileWatcher>::create();
+        watcher->start(tmpFile.fileName(), 5);
+        connect(watcher.data(), &FileWatcher::fileChanged, this, &EntryAttachments::attachmentFileModified);
+        m_attachmentFileWatchers.insert(tmpFile.fileName(), watcher);
+    }
+
+    const bool openOk = QDesktopServices::openUrl(QUrl::fromLocalFile(m_openedAttachments.value(key)));
+    if (!openOk && errorMessage) {
+        *errorMessage = tr("Cannot open file \"%1\"").arg(key);
+        return false;
+    }
+
+    return true;
+}
+
+void EntryAttachments::attachmentFileModified(const QString& path)
+{
+    auto it = m_openedAttachmentsInverse.find(path);
+    if (it != m_openedAttachmentsInverse.end()) {
+        emit valueModifiedExternally(it.value(), path);
+    }
+}
diff --git a/src/core/EntryAttachments.h b/src/core/EntryAttachments.h
index d23681b90..1fc35df89 100644
--- a/src/core/EntryAttachments.h
+++ b/src/core/EntryAttachments.h
@@ -18,10 +18,13 @@
 #ifndef KEEPASSX_ENTRYATTACHMENTS_H
 #define KEEPASSX_ENTRYATTACHMENTS_H
 
+#include "core/FileWatcher.h"
+#include "core/ModifiableObject.h"
+
+#include <QHash>
 #include <QMap>
 #include <QObject>
-
-#include "core/ModifiableObject.h"
+#include <QSharedPointer>
 
 class QStringList;
 
@@ -31,6 +34,7 @@ class EntryAttachments : public ModifiableObject
 
 public:
     explicit EntryAttachments(QObject* parent = nullptr);
+    virtual ~EntryAttachments();
     QList<QString> keys() const;
     bool hasKey(const QString& key) const;
     QSet<QByteArray> values() const;
@@ -45,9 +49,11 @@ public:
     bool operator==(const EntryAttachments& other) const;
     bool operator!=(const EntryAttachments& other) const;
     int attachmentsSize() const;
+    bool openAttachment(const QString& key, QString* errorMessage = nullptr);
 
 signals:
     void keyModified(const QString& key);
+    void valueModifiedExternally(const QString& key, const QString& path);
     void aboutToBeAdded(const QString& key);
     void added(const QString& key);
     void aboutToBeRemoved(const QString& key);
@@ -55,8 +61,16 @@ signals:
     void aboutToBeReset();
     void reset();
 
+private slots:
+    void attachmentFileModified(const QString& path);
+
 private:
+    void disconnectAndEraseExternalFile(const QString& path);
+
     QMap<QString, QByteArray> m_attachments;
+    QHash<QString, QString> m_openedAttachments;
+    QHash<QString, QString> m_openedAttachmentsInverse;
+    QHash<QString, QSharedPointer<FileWatcher>> m_attachmentFileWatchers;
 };
 
 #endif // KEEPASSX_ENTRYATTACHMENTS_H
diff --git a/src/gui/DatabaseWidget.cpp b/src/gui/DatabaseWidget.cpp
index 86dbea417..9daae9f88 100644
--- a/src/gui/DatabaseWidget.cpp
+++ b/src/gui/DatabaseWidget.cpp
@@ -329,6 +329,7 @@ void DatabaseWidget::clearAllWidgets()
     m_editEntryWidget->clear();
     m_historyEditEntryWidget->clear();
     m_editGroupWidget->clear();
+    m_previewView->clear();
 }
 
 void DatabaseWidget::emitCurrentModeChanged()
diff --git a/src/gui/EntryPreviewWidget.cpp b/src/gui/EntryPreviewWidget.cpp
index b7d783e6d..74fec6af5 100644
--- a/src/gui/EntryPreviewWidget.cpp
+++ b/src/gui/EntryPreviewWidget.cpp
@@ -94,6 +94,14 @@ EntryPreviewWidget::~EntryPreviewWidget()
 {
 }
 
+void EntryPreviewWidget::clear()
+{
+    hide();
+    m_currentEntry = nullptr;
+    m_currentGroup = nullptr;
+    m_ui->entryAttachmentsWidget->unlinkAttachments();
+}
+
 void EntryPreviewWidget::setEntry(Entry* selectedEntry)
 {
     if (!selectedEntry) {
@@ -339,7 +347,7 @@ void EntryPreviewWidget::updateEntryAdvancedTab()
     m_ui->entryAttributesTable->horizontalHeader()->setStretchLastSection(true);
     m_ui->entryAttributesTable->resizeColumnsToContents();
     m_ui->entryAttributesTable->resizeRowsToContents();
-    m_ui->entryAttachmentsWidget->setEntryAttachments(m_currentEntry->attachments());
+    m_ui->entryAttachmentsWidget->linkAttachments(m_currentEntry->attachments());
 }
 
 void EntryPreviewWidget::updateEntryAutotypeTab()
diff --git a/src/gui/EntryPreviewWidget.h b/src/gui/EntryPreviewWidget.h
index 335ef26e7..8a5b0c09f 100644
--- a/src/gui/EntryPreviewWidget.h
+++ b/src/gui/EntryPreviewWidget.h
@@ -40,6 +40,7 @@ public slots:
     void setEntry(Entry* selectedEntry);
     void setGroup(Group* selectedGroup);
     void setDatabaseMode(DatabaseWidget::Mode mode);
+    void clear();
 
 signals:
     void errorOccurred(const QString& error);
diff --git a/src/gui/entry/EditEntryWidget.cpp b/src/gui/entry/EditEntryWidget.cpp
index 5687351b5..9a70b2118 100644
--- a/src/gui/entry/EditEntryWidget.cpp
+++ b/src/gui/entry/EditEntryWidget.cpp
@@ -66,6 +66,7 @@ EditEntryWidget::EditEntryWidget(QWidget* parent)
     , m_sshAgentUi(new Ui::EditEntryWidgetSSHAgent())
     , m_historyUi(new Ui::EditEntryWidgetHistory())
     , m_browserUi(new Ui::EditEntryWidgetBrowser())
+    , m_attachments(new EntryAttachments())
     , m_customData(new CustomData())
     , m_mainWidget(new QScrollArea())
     , m_advancedWidget(new QWidget())
@@ -537,7 +538,7 @@ void EditEntryWidget::setupSSHAgent()
     connect(m_sshAgentUi->decryptButton, &QPushButton::clicked, this, &EditEntryWidget::decryptPrivateKey);
     connect(m_sshAgentUi->copyToClipboardButton, &QPushButton::clicked, this, &EditEntryWidget::copyPublicKey);
 
-    connect(m_advancedUi->attachmentsWidget->entryAttachments(), &EntryAttachments::modified,
+    connect(m_attachments.data(), &EntryAttachments::modified,
             this, &EditEntryWidget::updateSSHAgentAttachments);
     // clang-format on
 
@@ -576,7 +577,7 @@ void EditEntryWidget::updateSSHAgentAttachments()
 {
     // detect if KeeAgent.settings was removed by hand and reset settings
     if (m_entry && KeeAgentSettings::inEntryAttachments(m_entry->attachments())
-        && !KeeAgentSettings::inEntryAttachments(m_advancedUi->attachmentsWidget->entryAttachments())) {
+        && !KeeAgentSettings::inEntryAttachments(m_attachments.data())) {
         m_sshAgentSettings.reset();
         setSSHAgentSettings();
     }
@@ -584,8 +585,7 @@ void EditEntryWidget::updateSSHAgentAttachments()
     m_sshAgentUi->attachmentComboBox->clear();
     m_sshAgentUi->attachmentComboBox->addItem("");
 
-    auto attachments = m_advancedUi->attachmentsWidget->entryAttachments();
-    for (const QString& fileName : attachments->keys()) {
+    for (const QString& fileName : m_attachments->keys()) {
         if (fileName == "KeeAgent.settings") {
             continue;
         }
@@ -698,7 +698,7 @@ bool EditEntryWidget::getOpenSSHKey(OpenSSHKey& key, bool decrypt)
     if (!settings.toOpenSSHKey(m_mainUi->usernameComboBox->lineEdit()->text(),
                                m_mainUi->passwordEdit->text(),
                                m_db->filePath(),
-                               m_advancedUi->attachmentsWidget->entryAttachments(),
+                               m_attachments.data(),
                                key,
                                decrypt)) {
         showMessage(settings.errorString(), MessageWidget::Error);
@@ -828,6 +828,7 @@ void EditEntryWidget::loadEntry(Entry* entry,
 
 void EditEntryWidget::setForms(Entry* entry, bool restore)
 {
+    m_attachments->copyDataFrom(entry->attachments());
     m_customData->copyDataFrom(entry->customData());
 
     m_mainUi->titleEdit->setReadOnly(m_history);
@@ -888,7 +889,7 @@ void EditEntryWidget::setForms(Entry* entry, bool restore)
 
     m_mainUi->notesEdit->setPlainText(entry->notes());
 
-    m_advancedUi->attachmentsWidget->setEntryAttachments(entry->attachments());
+    m_advancedUi->attachmentsWidget->linkAttachments(m_attachments.data());
     m_entryAttributes->copyCustomKeysFrom(entry->attributes());
 
     if (m_attributesModel->rowCount() != 0) {
@@ -1090,7 +1091,6 @@ bool EditEntryWidget::commitEntry()
     }
 
     m_historyModel->setEntries(m_entry->historyItems());
-    m_advancedUi->attachmentsWidget->setEntryAttachments(m_entry->attachments());
 
     showMessage(tr("Entry updated successfully."), MessageWidget::Positive);
     setModified(false);
@@ -1110,7 +1110,7 @@ void EditEntryWidget::updateEntryData(Entry* entry) const
     QRegularExpression newLineRegex("(?:\r?\n|\r)");
 
     entry->attributes()->copyCustomKeysFrom(m_entryAttributes);
-    entry->attachments()->copyDataFrom(m_advancedUi->attachmentsWidget->entryAttachments());
+    entry->attachments()->copyDataFrom(m_attachments.data());
     entry->customData()->copyDataFrom(m_customData.data());
     entry->setTitle(m_mainUi->titleEdit->text().replace(newLineRegex, " "));
     entry->setUsername(m_mainUi->usernameComboBox->lineEdit()->text().replace(newLineRegex, " "));
@@ -1212,7 +1212,8 @@ void EditEntryWidget::clear()
     m_mainUi->notesEdit->clear();
 
     m_entryAttributes->clear();
-    m_advancedUi->attachmentsWidget->clearAttachments();
+    m_attachments->clear();
+    m_customData->clear();
     m_autoTypeAssoc->clear();
     m_historyModel->clear();
     m_iconsWidget->reset();
diff --git a/src/gui/entry/EditEntryWidget.h b/src/gui/entry/EditEntryWidget.h
index 47975ac6d..4616e1af5 100644
--- a/src/gui/entry/EditEntryWidget.h
+++ b/src/gui/entry/EditEntryWidget.h
@@ -35,6 +35,7 @@ class EditWidgetIcons;
 class EditWidgetProperties;
 class Entry;
 class EntryAttributes;
+class EntryAttachments;
 class EntryAttributesModel;
 class EntryHistoryModel;
 class QButtonGroup;
@@ -171,6 +172,7 @@ private:
     const QScopedPointer<Ui::EditEntryWidgetSSHAgent> m_sshAgentUi;
     const QScopedPointer<Ui::EditEntryWidgetHistory> m_historyUi;
     const QScopedPointer<Ui::EditEntryWidgetBrowser> m_browserUi;
+    const QScopedPointer<EntryAttachments> m_attachments;
     const QScopedPointer<CustomData> m_customData;
 
     QScrollArea* const m_mainWidget;
diff --git a/src/gui/entry/EntryAttachmentsModel.h b/src/gui/entry/EntryAttachmentsModel.h
index 486ee059f..d155f25ca 100644
--- a/src/gui/entry/EntryAttachmentsModel.h
+++ b/src/gui/entry/EntryAttachmentsModel.h
@@ -19,6 +19,7 @@
 #define KEEPASSX_ENTRYATTACHMENTSMODEL_H
 
 #include <QAbstractListModel>
+#include <QPointer>
 
 class EntryAttachments;
 
@@ -55,7 +56,7 @@ private slots:
     void setReadOnly(bool readOnly);
 
 private:
-    EntryAttachments* m_entryAttachments;
+    QPointer<EntryAttachments> m_entryAttachments;
     QStringList m_headers;
     bool m_readOnly = false;
 };
diff --git a/src/gui/entry/EntryAttachmentsWidget.cpp b/src/gui/entry/EntryAttachmentsWidget.cpp
index 5d1e9240a..bab041d88 100644
--- a/src/gui/entry/EntryAttachmentsWidget.cpp
+++ b/src/gui/entry/EntryAttachmentsWidget.cpp
@@ -1,14 +1,30 @@
+/*
+ *  Copyright (C) 2021 KeePassXC Team <team@keepassxc.org>
+ *
+ *  This program is free software: you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation, either version 2 or (at your option)
+ *  version 3 of the License.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
 #include "EntryAttachmentsWidget.h"
 #include "ui_EntryAttachmentsWidget.h"
 
-#include <QDesktopServices>
 #include <QDir>
 #include <QDropEvent>
 #include <QMimeData>
+#include <QStandardPaths>
 #include <QTemporaryFile>
 
 #include "EntryAttachmentsModel.h"
-#include "config-keepassx.h"
 #include "core/Config.h"
 #include "core/EntryAttachments.h"
 #include "core/Tools.h"
@@ -18,7 +34,7 @@
 EntryAttachmentsWidget::EntryAttachmentsWidget(QWidget* parent)
     : QWidget(parent)
     , m_ui(new Ui::EntryAttachmentsWidget)
-    , m_entryAttachments(new EntryAttachments(this))
+    , m_entryAttachments(nullptr)
     , m_attachmentsModel(new EntryAttachmentsModel(this))
     , m_readOnly(false)
     , m_buttonsVisible(true)
@@ -29,7 +45,6 @@ EntryAttachmentsWidget::EntryAttachmentsWidget(QWidget* parent)
     m_ui->attachmentsView->viewport()->setAcceptDrops(true);
     m_ui->attachmentsView->viewport()->installEventFilter(this);
 
-    m_attachmentsModel->setEntryAttachments(m_entryAttachments);
     m_ui->attachmentsView->setModel(m_attachmentsModel);
     m_ui->attachmentsView->verticalHeader()->hide();
     m_ui->attachmentsView->horizontalHeader()->setStretchLastSection(true);
@@ -63,7 +78,7 @@ EntryAttachmentsWidget::~EntryAttachmentsWidget()
 {
 }
 
-const EntryAttachments* EntryAttachmentsWidget::entryAttachments() const
+const EntryAttachments* EntryAttachmentsWidget::attachments() const
 {
     return m_entryAttachments;
 }
@@ -78,15 +93,29 @@ bool EntryAttachmentsWidget::isButtonsVisible() const
     return m_buttonsVisible;
 }
 
-void EntryAttachmentsWidget::setEntryAttachments(const EntryAttachments* attachments)
+void EntryAttachmentsWidget::linkAttachments(EntryAttachments* attachments)
 {
-    Q_ASSERT(attachments != nullptr);
-    m_entryAttachments->copyDataFrom(attachments);
+    unlinkAttachments();
+
+    m_entryAttachments = attachments;
+    m_attachmentsModel->setEntryAttachments(m_entryAttachments);
+
+    if (m_entryAttachments) {
+        connect(m_entryAttachments,
+                SIGNAL(valueModifiedExternally(QString, QString)),
+                this,
+                SLOT(attachmentModifiedExternally(QString, QString)));
+        connect(m_entryAttachments, SIGNAL(modified()), this, SIGNAL(widgetUpdated()));
+    }
 }
 
-void EntryAttachmentsWidget::clearAttachments()
+void EntryAttachmentsWidget::unlinkAttachments()
 {
-    m_entryAttachments->clear();
+    if (m_entryAttachments) {
+        m_entryAttachments->disconnect(this);
+        m_entryAttachments = nullptr;
+        m_attachmentsModel->setEntryAttachments(nullptr);
+    }
 }
 
 void EntryAttachmentsWidget::setReadOnly(bool readOnly)
@@ -109,25 +138,9 @@ void EntryAttachmentsWidget::setButtonsVisible(bool buttonsVisible)
     emit buttonsVisibleChanged(m_buttonsVisible);
 }
 
-QByteArray EntryAttachmentsWidget::getAttachment(const QString& name)
-{
-    return m_entryAttachments->value(name);
-}
-
-void EntryAttachmentsWidget::setAttachment(const QString& name, const QByteArray& value)
-{
-    m_entryAttachments->set(name, value);
-}
-
-void EntryAttachmentsWidget::removeAttachment(const QString& name)
-{
-    if (!isReadOnly() && m_entryAttachments->hasKey(name)) {
-        m_entryAttachments->remove(name);
-    }
-}
-
 void EntryAttachmentsWidget::insertAttachments()
 {
+    Q_ASSERT(m_entryAttachments);
     Q_ASSERT(!isReadOnly());
     if (isReadOnly()) {
         return;
@@ -153,6 +166,7 @@ void EntryAttachmentsWidget::insertAttachments()
 
 void EntryAttachmentsWidget::removeSelectedAttachments()
 {
+    Q_ASSERT(m_entryAttachments);
     Q_ASSERT(!isReadOnly());
     if (isReadOnly()) {
         return;
@@ -181,11 +195,14 @@ void EntryAttachmentsWidget::removeSelectedAttachments()
 
 void EntryAttachmentsWidget::renameSelectedAttachments()
 {
+    Q_ASSERT(m_entryAttachments);
     m_ui->attachmentsView->edit(m_ui->attachmentsView->selectionModel()->selectedIndexes().first());
 }
 
 void EntryAttachmentsWidget::saveSelectedAttachments()
 {
+    Q_ASSERT(m_entryAttachments);
+
     const QModelIndexList indexes = m_ui->attachmentsView->selectionModel()->selectedRows(0);
     if (indexes.isEmpty()) {
         return;
@@ -253,7 +270,7 @@ void EntryAttachmentsWidget::openAttachment(const QModelIndex& index)
     }
 
     QString errorMessage;
-    if (!openAttachment(index, errorMessage)) {
+    if (!m_entryAttachments->openAttachment(m_attachmentsModel->keyByIndex(index), &errorMessage)) {
         errorOccurred(tr("Unable to open attachment:\n%1").arg(errorMessage));
     }
 }
@@ -268,7 +285,7 @@ void EntryAttachmentsWidget::openSelectedAttachments()
     QStringList errors;
     for (const QModelIndex& index : indexes) {
         QString errorMessage;
-        if (!openAttachment(index, errorMessage)) {
+        if (!m_entryAttachments->openAttachment(m_attachmentsModel->keyByIndex(index), &errorMessage)) {
             const QString filename = m_attachmentsModel->keyByIndex(index);
             errors.append(QString("%1 - %2").arg(filename, errorMessage));
         };
@@ -324,39 +341,6 @@ bool EntryAttachmentsWidget::insertAttachments(const QStringList& filenames, QSt
     return errors.isEmpty();
 }
 
-bool EntryAttachmentsWidget::openAttachment(const QModelIndex& index, QString& errorMessage)
-{
-    const QString filename = m_attachmentsModel->keyByIndex(index);
-    const QByteArray attachmentData = m_entryAttachments->value(filename);
-
-    // tmp file will be removed once the database (or the application) has been closed
-#ifdef KEEPASSXC_DIST_SNAP
-    const QString tmpFileTemplate =
-        QString("%1/XXXXXX.%2").arg(QProcessEnvironment::systemEnvironment().value("SNAP_USER_DATA"), filename);
-#else
-    const QString tmpFileTemplate = QDir::temp().absoluteFilePath(QString("XXXXXX.").append(filename));
-#endif
-
-    QScopedPointer<QTemporaryFile> tmpFile(new QTemporaryFile(tmpFileTemplate, this));
-
-    const bool saveOk = tmpFile->open() && tmpFile->write(attachmentData) == attachmentData.size() && tmpFile->flush();
-    if (!saveOk) {
-        errorMessage = QString("%1 - %2").arg(filename, tmpFile->errorString());
-        return false;
-    }
-
-    tmpFile->close();
-    const bool openOk = QDesktopServices::openUrl(QUrl::fromLocalFile(tmpFile->fileName()));
-    if (!openOk) {
-        errorMessage = QString("Can't open file \"%1\"").arg(filename);
-        return false;
-    }
-
-    // take ownership of the tmpFile pointer
-    tmpFile.take();
-    return true;
-}
-
 QStringList EntryAttachmentsWidget::confirmLargeAttachments(const QStringList& filenames)
 {
     const QString confirmation(tr("%1 is a big file (%2 MB).\nYour database may get very large and reduce "
@@ -421,3 +405,34 @@ bool EntryAttachmentsWidget::eventFilter(QObject* watched, QEvent* e)
 
     return QWidget::eventFilter(watched, e);
 }
+
+void EntryAttachmentsWidget::attachmentModifiedExternally(const QString& key, const QString& filePath)
+{
+    if (m_pendingChanges.contains(filePath)) {
+        return;
+    }
+
+    m_pendingChanges << filePath;
+
+    auto result = MessageBox::question(
+        this,
+        tr("Attachment modified"),
+        tr("The attachment '%1' was modified.\nDo you want to save the changes to your database?").arg(key),
+        MessageBox::Save | MessageBox::Discard,
+        MessageBox::Save);
+
+    if (result == MessageBox::Save) {
+        QFile f(filePath);
+        if (f.open(QFile::ReadOnly)) {
+            m_entryAttachments->set(key, f.readAll());
+            f.close();
+            emit widgetUpdated();
+        } else {
+            MessageBox::critical(this,
+                                 tr("Saving attachment failed"),
+                                 tr("Saving updated attachment failed.\nError: %1").arg(f.errorString()));
+        }
+    }
+
+    m_pendingChanges.removeAll(filePath);
+}
diff --git a/src/gui/entry/EntryAttachmentsWidget.h b/src/gui/entry/EntryAttachmentsWidget.h
index b959d7c71..53d5076e2 100644
--- a/src/gui/entry/EntryAttachmentsWidget.h
+++ b/src/gui/entry/EntryAttachmentsWidget.h
@@ -1,3 +1,20 @@
+/*
+ *  Copyright (C) 2021 KeePassXC Team <team@keepassxc.org>
+ *
+ *  This program is free software: you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation, either version 2 or (at your option)
+ *  version 3 of the License.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
 #ifndef ENTRYATTACHMENTSWIDGET_H
 #define ENTRYATTACHMENTSWIDGET_H
 
@@ -22,17 +39,13 @@ public:
     explicit EntryAttachmentsWidget(QWidget* parent = nullptr);
     ~EntryAttachmentsWidget();
 
-    const EntryAttachments* entryAttachments() const;
+    const EntryAttachments* attachments() const;
     bool isReadOnly() const;
     bool isButtonsVisible() const;
 
-    QByteArray getAttachment(const QString& name);
-    void setAttachment(const QString& name, const QByteArray& value);
-    void removeAttachment(const QString& name);
-
 public slots:
-    void setEntryAttachments(const EntryAttachments* attachments);
-    void clearAttachments();
+    void linkAttachments(EntryAttachments* attachments);
+    void unlinkAttachments();
     void setReadOnly(bool readOnly);
     void setButtonsVisible(bool isButtonsVisible);
 
@@ -51,10 +64,10 @@ private slots:
     void openSelectedAttachments();
     void updateButtonsVisible();
     void updateButtonsEnabled();
+    void attachmentModifiedExternally(const QString& key, const QString& filePath);
 
 private:
     bool insertAttachments(const QStringList& fileNames, QString& errorMessage);
-    bool openAttachment(const QModelIndex& index, QString& errorMessage);
 
     QStringList confirmLargeAttachments(const QStringList& filenames);
 
@@ -63,6 +76,7 @@ private:
     QScopedPointer<Ui::EntryAttachmentsWidget> m_ui;
     QPointer<EntryAttachments> m_entryAttachments;
     QPointer<EntryAttachmentsModel> m_attachmentsModel;
+    QStringList m_pendingChanges;
     bool m_readOnly;
     bool m_buttonsVisible;
 };