OK, since it can spread lycanthropy, it appears to be a natural lycanthrope.
Plugging the stats above into the lycanthrope template yields...
Size and Type: The base creature’s type does not change, but the creature gains the shapechanger subtype.
A lycanthrope uses either the base creature’s or the dire mouse's statistics and special abilities in addition to those described here.
Hit Dice and Hit Points: Same as the base creature.
Speed: Same as the base creature or base animal, depending on which form the weremouse is using. Hybrids use the base creature’s speed.
Armor Class: The base creature’s natural armor bonus increases by +2 in all forms. In hybrid form, the weremouse's natural armor bonus is equal to the natural armor bonus of the base animal or the base creature, whichever is better.
Base Attack/Grapple: As the base base creature. The weremouse's grapple bonus uses its attack bonus and modifiers for Strength and size depending on the weremouse's form.
Attacks: Same as the base creature or base animal, depending on which form the weremouse is using. A weremouse in hybrid form gains two claw attacks and a bite attack as natural weapons. These weapons deal damage based on the hybrid form’s size. A hybrid may attack with a weapon and a bite, or may attack with its natural weapons. The bite attack of a hybrid is a secondary attack.
Hybrid Size Claw Bite
Small 1d3 1d4
Medium 1d4 1d6
Large 1d6 1d8
Huge 2d4 2d6
Damage: Same as the base creature or base animal, depending on which form the weremouse is in.
Special Attacks: A weremouse retains the special attacks of the base creature or base animal, depending on which form it is using, and also gains the special attacks described below.
A weremouse's hybrid form does not gain any special attacks of the base animal. A weremouse spellcaster cannot cast spells with verbal, somatic, or material components while in animal form, or spells with verbal components while in hybrid form.
Curse of Lycanthropy (Su): Any humanoid or giant hit by a weremouse's bite attack in animal or hybrid form must succeed on a DC 15 Fortitude save or contract lycanthropy. If the victim’s size is not within one size category of the weremouse the victim cannot contract lycanthropy from that weremouse. Afflicted lycanthropes cannot pass on the curse of lycanthropy.
Special Qualities: A weremouse retains all the special qualities of the base creature and the base animal, and also gains those described below.
Alternate Form (Su): A weremouse can assume the form of a dire mouse. It does not assume the ability scores of the animal, but instead adds the animal’s physical ability score modifiers to its own ability scores. A weremouse also can assume a bipedal hybrid form with prehensile hands and animalistic features.
Changing to or from dire mouse or hybrid form is a standard action. A slain weremouse reverts to its humanoid form, although it remains dead. Separated body parts retain their animal form, however. Afflicted lycanthropes find this ability difficult to control (see Lycanthropy as an Affliction, below), but natural lycanthropes have full control over this power.
Damage Reduction (Ex): A weremouse in animal or hybrid form has damage reduction 10/silver.
Mouse Empathy (Ex): In any form, weremice can communicate and empathize with normal or dire mice. This gives them a +4 racial bonus on checks when influencing the animal’s attitude and allows the communication of simple concepts and (if the animal is friendly) commands, such as "friend," "foe," "flee," and "attack."
Low-Light Vision (Ex): A weremouse has low-light vision in any form.
Scent (Ex): A weremouse has the scent ability in any form.
Base Save Bonuses: Increase the base save bonuses of the base creature as follows: Fort +2, Ref +2.
Abilities: Weremice gain +2 to Wisdom. In addition, when in animal form, a weremouse's physical ability scores are adjusted as follows: Dex +6. A weremouse in hybrid form modifies its physical ability scores by the same amount.
In addition, a weremouse may also gain an additional ability score increase by virtue of its extra Hit Dice.
Skills: A weremouse gains skill points equal to (2 + Int modifier, minimum 1), as if it had multiclassed into dire mouse. (Animal is never its first Hit Die, though, and it does not gain quadruple skill points for any animal Hit Die.) Balance, Climb, Hide, Jump, Move Silently, and Swim are class skills for the weremouse's animal levels. In any form, a weremouse has a +4 racial bonus on Hide checks and a +8 racial bonus on Balance, Climb, Jump, Move Silently, and Swim checks.
Feats: Add Stealthy and Weapon Finesse to the base creature’s feats. If this results in it having the same feat twice, the weremouse gains no additional benefit unless the feat normally can be taken more once, in which case the duplicated feat works as noted in the feat description. This process may give the weremouse more feats than a character of its total Hit Dice would normally be entitled to; if this occurs, any “extra” feats are denoted as bonus feats.
It’s possible that a weremouse cannot meet the prerequisites for all its feats when in humanoid form. If this occurs, the weremouse still has the feats, but cannot use them when in humanoid form. A weremouse receives Iron Will as a bonus feat.
Environment: Same as the base creature.
Organization: Solitary or pair, sometimes family (3–4), pack (6–10), or troupe (family plus related animals)
Challenge Rating: By class level or base creature, +2.
Treasure: Standard.
Alignment: Often neutral.
Advancement: By character class.
Level Adjustment: Same as the base creature +2 (afflicted) or +3 (natural). In addition, a lycanthrope’s character level is increased by the number of racial Hit Dice the base animal has.