diff --git a/zone/entity.cpp b/zone/entity.cpp
index 28bb5e144..8d182fff5 100644
--- a/zone/entity.cpp
+++ b/zone/entity.cpp
@@ -5237,6 +5237,11 @@ std::vector<Mob*> EntityList::GetTargetsForVirusEffect(Mob *spreader, Mob *origi
 	bool               is_detrimental_spell = IsDetrimentalSpell(spell_id);
 	for (auto          &it : entity_list.GetCloseMobList(spreader, range)) {
 		Mob *mob = it.second;
+
+		if (!mob) { 
+			continue; 
+		}
+
 		if (mob == spreader) {
 			continue;
 		}
@@ -5259,6 +5264,10 @@ std::vector<Mob*> EntityList::GetTargetsForVirusEffect(Mob *spreader, Mob *origi
 		// Make sure the target is in range
 		if (mob->CalculateDistance(spreader->GetX(), spreader->GetY(), spreader->GetZ()) <= range) {
 
+			if (!original_caster) {
+				continue;
+			}
+
 			//Do not allow detrimental spread to anything the original caster couldn't normally attack.
 			if (is_detrimental_spell && !original_caster->IsAttackAllowed(mob, true)) {
 				continue;
diff --git a/zone/spell_effects.cpp b/zone/spell_effects.cpp
index 44a02fbdd..da3b45fe1 100644
--- a/zone/spell_effects.cpp
+++ b/zone/spell_effects.cpp
@@ -8591,6 +8591,11 @@ void Mob::VirusEffectProcess()
 void Mob::SpreadVirusEffect(int32 spell_id, uint32 caster_id, int32 buff_tics_remaining)
 {
 	Mob *caster = entity_list.GetMob(caster_id);
+
+	if (!caster) {
+		return;
+	}
+
 	std::vector<Mob *> targets_in_range = entity_list.GetTargetsForVirusEffect(
 		this,
 		caster,