diff --git a/rules/linux/auditd/lnx_auditd_alter_bash_profile.yml b/rules/linux/auditd/lnx_auditd_alter_bash_profile.yml
new file mode 100644
index 000000000..f974b4585
--- /dev/null
+++ b/rules/linux/auditd/lnx_auditd_alter_bash_profile.yml
@@ -0,0 +1,30 @@
+title: Detects Suspicious edit of .bash_profile and .bashrc on Linux systems
+status: experimental
+description: Detects change of user environment. Adversaries can insert code into these files to gain persistence each time a user logs in or opens a new shell.
+references:
+    - 'MITRE Attack technique T1156; .bash_profile and .bashrc. '
+date: 2019/05/12
+tags:
+    - attack.s0003
+    - attack.t1156
+    - attack.persistence
+author: Peter Matkovski
+logsource:
+    product: linux
+    service: auditd
+detection:
+    selection:
+        type: 'PATH'
+        name:
+            - '/home/*/.bashrc'
+            - '/home/*/.bash_profile' 
+            - '/home/*/.profile'
+            - '/etc/profile'
+            - '/etc/shells'
+            - '/etc/bashrc'
+            - '/etc/csh.cshrc'
+            - '/etc/csh.login'
+    condition: selection
+falsepositives:
+    - Admin or User activity
+level: medium
diff --git a/tools/sigma/backends/elasticsearch.py b/tools/sigma/backends/elasticsearch.py
index 2c93283a8..cfcd12af7 100644
--- a/tools/sigma/backends/elasticsearch.py
+++ b/tools/sigma/backends/elasticsearch.py
@@ -249,7 +249,10 @@ class ElasticsearchDSLBackend(RulenameCommentMixin, ElasticsearchWildcardHandlin
             dateField = self.sigmaconfig.config['dateField']
         if self.interval:
             if 'bool' not in self.queries[-1]['query']['constant_score']['filter']:
+                saved_simple_query = self.queries[-1]['query']['constant_score']['filter']
                 self.queries[-1]['query']['constant_score']['filter'] = {'bool': {'must': []}}
+                if len(saved_simple_query.keys()) > 0:
+                    self.queries[-1]['query']['constant_score']['filter']['bool']['must'].append(saved_simple_query)
             if 'must' not in self.queries[-1]['query']['constant_score']['filter']['bool']:
                 self.queries[-1]['query']['constant_score']['filter']['bool']['must'] = []