diff --git a/backup/moodle2/backup_stepslib.php b/backup/moodle2/backup_stepslib.php
index 6dbe0731701..7439b27a71d 100644
--- a/backup/moodle2/backup_stepslib.php
+++ b/backup/moodle2/backup_stepslib.php
@@ -1714,9 +1714,22 @@ class backup_zip_contents extends backup_execution_step implements file_progress
         $zippacker = get_file_packer('application/vnd.moodle.backup');
 
         // Zip files
-        $zippacker->archive_to_pathname($files, $zipfile, true, $this);
+        $result = $zippacker->archive_to_pathname($files, $zipfile, true, $this);
 
-        // If any progress happened, end it.
+        // Something went wrong.
+        if ($result === false) {
+            @unlink($zipfile);
+            throw new backup_step_exception('error_zip_packing', '', 'An error was encountered while trying to generate backup zip');
+        }
+        // Read to make sure it is a valid backup. Refer MDL-37877 . Delete it, if found not to be valid.
+        try {
+            backup_general_helper::get_backup_information_from_mbz($zipfile);
+        } catch (backup_helper_exception $e) {
+            @unlink($zipfile);
+            throw new backup_step_exception('error_zip_packing', '', $e->debuginfo);
+        }
+
+            // If any progress happened, end it.
         if ($this->startedprogress) {
             $this->task->get_progress()->end_progress();
         }
diff --git a/backup/util/helper/backup_cron_helper.class.php b/backup/util/helper/backup_cron_helper.class.php
index a49ee7bebad..949565a8415 100644
--- a/backup/util/helper/backup_cron_helper.class.php
+++ b/backup/util/helper/backup_cron_helper.class.php
@@ -377,7 +377,11 @@ abstract class backup_cron_automated_helper {
 
         $outcome = self::BACKUP_STATUS_OK;
         $config = get_config('backup');
-        $bc = new backup_controller(backup::TYPE_1COURSE, $course->id, backup::FORMAT_MOODLE, backup::INTERACTIVE_NO, backup::MODE_AUTOMATED, $userid);
+        $dir = $config->backup_auto_destination;
+        $storage = (int)$config->backup_auto_storage;
+
+        $bc = new backup_controller(backup::TYPE_1COURSE, $course->id, backup::FORMAT_MOODLE, backup::INTERACTIVE_NO,
+                backup::MODE_AUTOMATED, $userid);
 
         try {
 
@@ -402,27 +406,28 @@ abstract class backup_cron_automated_helper {
                 }
             }
 
-            // Set the default filename
+            // Set the default filename.
             $format = $bc->get_format();
             $type = $bc->get_type();
             $id = $bc->get_id();
             $users = $bc->get_plan()->get_setting('users')->get_value();
             $anonymised = $bc->get_plan()->get_setting('anonymize')->get_value();
-            $bc->get_plan()->get_setting('filename')->set_value(backup_plan_dbops::get_default_backup_filename($format, $type, $id, $users, $anonymised));
+            $bc->get_plan()->get_setting('filename')->set_value(backup_plan_dbops::get_default_backup_filename($format, $type,
+                    $id, $users, $anonymised));
 
             $bc->set_status(backup::STATUS_AWAITING);
 
             $bc->execute_plan();
             $results = $bc->get_results();
             $outcome = self::outcome_from_results($results);
-            $file = $results['backup_destination']; // may be empty if file already moved to target location
-            $dir = $config->backup_auto_destination;
-            $storage = (int)$config->backup_auto_storage;
+            $file = $results['backup_destination']; // May be empty if file already moved to target location.
             if (!file_exists($dir) || !is_dir($dir) || !is_writable($dir)) {
                 $dir = null;
             }
-            if ($file && !empty($dir) && $storage !== 0) {
-                $filename = backup_plan_dbops::get_default_backup_filename($format, $type, $course->id, $users, $anonymised, !$config->backup_shortname);
+            // Copy file only if there was no error.
+            if ($file && !empty($dir) && $storage !== 0 && $outcome != self::BACKUP_STATUS_ERROR) {
+                $filename = backup_plan_dbops::get_default_backup_filename($format, $type, $course->id, $users, $anonymised,
+                        !$config->backup_shortname);
                 if (!$file->copy_content_to($dir.'/'.$filename)) {
                     $outcome = self::BACKUP_STATUS_ERROR;
                 }
@@ -438,6 +443,20 @@ abstract class backup_cron_automated_helper {
             $outcome = self::BACKUP_STATUS_ERROR;
         }
 
+        // Delete the backup file immediately if something went wrong.
+        if ($outcome === self::BACKUP_STATUS_ERROR) {
+
+            // Delete the file from file area if exists.
+            if (!empty($file)) {
+                $file->delete();
+            }
+
+            // Delete file from external storage if exists.
+            if ($storage !== 0 && !empty($filename) && file_exists($dir.'/'.$filename)) {
+                @unlink($dir.'/'.$filename);
+            }
+        }
+
         $bc->destroy();
         unset($bc);